Evolt

"I'm the game maker. I derive the best strategy by considering every possibility. Everything is going as planned."

- Blood Stalk to Night Rogue.

"Even if I had never come to Earth, you people would've found yourselves causing another war soon enough. I remember telling you this before. Science always ends up causing destruction! Scientific advancement makes life more convenient, and people start to take things for granted. Before they know it, they will find themselves embroiled in war. That's the future...that science promises!"

- Kamen Rider Evol's speech to Build.

"Your faces full of despair are delightful! I may as well take the chance to savor the horror you'll feel as your life inevitably reaches its end."

- Evolt as he is destroying Earth with one of his black holes.

Evolt is one of the leaders of the Faust organization and the primary antagonist of Kamen Rider Build. He initially appears as a subordinate of Night Rogue but is eventually revealed to be manipulating all sides of the Japanese Civil War towards his own goal of constructing the Pandora Tower and using it to wipe out all life on Earth.

Evolt is a mysterious entity who annihilated the ancient civilization on Mars long ago using the power of the Pandora Box. After lying dormant on Mars for millions of years following this, he took over the body of Soichi Isurugi, owner of the cafe nascita and secretly the astronaut who discovered the Pandora Box on Mars 10 years ago, and used him to trigger the Skywall Disaster that separated Japan.

After he re-obtains the Evol Driver, Evolt is granted the power to transform into Kamen Rider Evol. From there, Evolt completes the Evol Trigger and uses it to assume his Black Hole form, the form with which he used to annihilate Mars. Evolt then begins working to complete the Black Pandora Panel with the 10 Lost Fullbottles so he can absorb it to achieve his complete form, allowing him to move planet-to-planet via warp travel to consume them without having to expend a large amount of energy in order to travel across space. With this power, Evolt intends to destroy everything in the galaxy and leave only himself to create a "new world".

In the movie Kamen Rider Build: Be The One, Evolt is revealed as a member of an enigmatic extraterrestrial clan known as the Blood Tribe who travel the universe devouring planets to increase their own power. It is later revealed in Kamen Rider Build NEW WORLD: Cross-Z that Evolt is at odds with his older brother Killbus, the king of the Blood Tribe.

Evolt is voiced by Tetsuo Kanao, who has dubbed several other villains in Japanese, including Inspector Javert in the 1998 adaptation of Les Misérables, Vilos Cohaagen in the 2012 Total Recall remake and Tywin Lannister in Game of Thrones. As Soichi Isurugi, Evolt is portrayed by Yasuyuki Maekawa. As Masakuni Mido, Evolt is portrayed by Norimasa Fuke.

Past
Hailing from Planet Blood, Evolt's older brother Killbus, the king of the Blood Tribe, destroyed their home world and sent out the remaining members of the tribe to destroy other planets in the universe. However, before Killbus could finish destroying the planet, Evolt stole their planet's power source, the Pandora Box. Evolt thus roamed the galaxy annihilating countless worlds and consuming their energy to become more powerful.

In the ancient past, Evolt used Pandora Box to create the Pandora Tower and annihilate the civilization of Mars with a massive distortion. To prevent him from moving on to other planets, Vernage, the Queen of Mars, fragmented Evolt's spirit from his body and sealed his power away in the Pandora Box.

Millions of years after the destruction of Mars, a fragment of Evolt's essence traveled to Earth after a probe sent from there came to Mars. Once the probe returned to a building owned by Namba Heavy Industries Ltd., Evolt's essence entered the womb of a security guard for the probe, Yuri Banjou, and fused with her unborn son Ryuga. Ryuga was born a month later, containing the essence inside him though it did not influence his personality. At some point Evolt had Ryuga's parents killed in order to spur his emotions and increase his Hazard Level.

10 years prior to the events of Build, Soichi Isurugi, an astronaut working with the Kiwami Project, discovered the Pandora Box while on an expedition to Mars. Soichi unwittingly released Evolt's consciousness and possessed by him. At the ceremony back on Earth, under Evolt's control, Isurugi applied his hand to the Pandora Box, causing the Sky Wall Disaster.

Evolt was later arrested and placed in a mental hospital, along with his host's daughter, Misora Isurugi, who was also exposed to the box and gained the ability to purify Fullbottles.

Forming Faust
However, Evolt escaped about a month later and went to Shinobu Katsuragi to get him to invent the Lost Bottles and the Rider System. Searching for ideas for the 60 empty Fullbottles he had, Evolt probed Soichi's mind for the 30 Organic Fullbottles, with Soichi offering up things Misora liked such as animals. Evolt then asked Soichi for things that could destroy those 30 things to use for the 30 Inorganic Fullbottles, to which Soichi initially offered up tanks and other weapons, but later switched random things likes comics to avoid bringing harm to the things that Misora liked.

7 years later, Soichi was appointed as a special consultant for the Pandora Box. He later approached Gentoku Himuro and Takumi Katsuragi, who were leading a cabal of scientists to conduct secret experiments with Nebula Gas. After neutralizing a Fang Smash created as a side effect of one of their experiments, Gentoku recognized Soichi as the astronaut who had caused the Skywall Disaster. Isurugi then informs Gentoku that he was sent by Namba Heavy Industries Ltd. to assist them in their research of the Pandora Box and offers that he become Gentoku's right-hand man, but Gentoku declines, not trusting Isurugi.

Evolt later kills Gentoku's best friend Koji Hotei and drops his dead body before him. Having grown resentful towards Hotei for being chosen by his father to be his successor as Prime Minister instead of him, Gentoku ends up reacting gleefully to Hotei's death and accepts Soichi's offer to work with him, leading to them forming Faust along with Takumi Katsuragi from the scientists they had gathered to conduct unsanctioned experiments.

Evolt eventually convinced Soichi's daughter Misora to join Faust to purify the Fullbottles for them, lying to her and saying it was for a benevolent cause. When she eventually found out about Faust's intentions, she lost her will to continue working for them. "Soichi" then "saved" her and took her back to the cafe, where he convinced her to continue purifying the bottles for good.

Evolt later stole the Pandora Box panels from the Touto Institute of Advanced Matter Physics to ensure their confidence and plastered into one of nascita's basement walls. He also took along a Build Driver and some Fullbottles from Faust.

Disposing of Katsuragi
When Takumi Katsuragi attempted to quit Faust, Blood Stalk knocked him out and switched his clothes and face with Taro Satou, whom Stalk had previously killed by Stalk. Stalk then left Taro Satou in the alleyway and erased Takumi's memories before talking him back to Faust to experiment on him. On September 5th, Isurugi brought the amnesiac Katsuragi to a small alleyway. After Takumi woke up, Soichi renamed him "Sento Kiryu" and guided him to become Kamen Rider Build so that, with Build fighting more monsters, Soichi would have reasons to have Misora purify more bottles.

Encounters with Build
Blood Stalk was first seen by Build when he showed up to take Masahiro Nabeshima after he was reverted from his form as the Mirage Smash by Build. He injected Sento in the back with poison that left him stunned and unable to do anything while Stalk retrieved the unconscious Nabeshima.

Later, Stalk showed up again as Build was fighting the Square Smash. Stalk stood up from the park bench he was sitting on and fired a Devil Steam from his Steam Rifle at the Square Smash, causing it to grow giant. After observing Build fight and defeat the Smash, Stalk leaves and returns to Faust's lair. Night Rogue questions Stalk as to why he didn't kill Build, but Blood Stalk assures him that Build being left alive is all according to plan.

Stalk later informed Night Rogue that Build's Hazard Level was increasing. Rogue ponders what Stalk is planing, but Stalk simply states that he hungers for more strength and that Build must learn more about himself before proceeding to the next stage. When Sento and Ryuga infiltrate one of Faust's hideouts, Blood Stalk shoots one of their captive test subjects to prevent him from leaving and shouts at the others to be quiet. Ryuga attempts to attack Stalk, but Stalk grabs Ryuga and injects him with poison. As Sento runs over to Ryuga, Stalk reveals to Sento that he was injected with a large dosage of the Nebula gas, but didn't transform into a Smash, and that it's the Nebula Gas within him that makes him able to transform into a Kamen Rider. Sento then transforms into Build RabbitTank and pummels Stalk, demanding to know whom injected him with the gas and erased his memory. Stalk simply laughs and tells Build he loses perspective when it comes to his lost memory before shooting him with his Transteam gun,knocking Build away and cancelling his transformation. Stalk then evacuates the lair and has his Faust Guardians take the human captives with them. Stalk was later called by Night Rogue and informs him Sento now knows of what took place in the lab. Rogue ponders how long they intend to let Sento run free, but Stalk tells him they will deal with Sento in time and that right now the next phase of their plan will be more interesting before tossing the phone away.

At one of Faust's hideouts, Blood Stalk tells Gentoku Himuro and Nariaki Utsumi that Sento plans to head to Hokuto and that it would disrupt their plan to utilize the Kamen Rider System as a military weapon if Sento got caught by the Hokuto government. Gentoku states he will go to the Skyroad to stop Sento and asks Stalk to accompany him. Stalk at first declines, so Gentoku turns into Night Rogue and attacks Stalk, prompting Stalk to agree to accompany Rogue.

Stalk initially watched from afar as Rogue and two Faust Guardians intercept a family from Hokuto to use as captives to lure out Sento. Transformed into Build RabbitTank, Sento fights Rogue while Ryuga deals with the Faust Guardians. Backed into a corner by Build, Rogue calls on to assist and stop Sento and Ryuga. Stalk inserts the Rocket bottle into his Steam Rifle and inserted and performs a Steam Attack in such a way that rebounds towards Rogue, distracting him and allowing Stalk to leave to go to Hokuto.

As Sento and Ryuga are talking to Kyoka Katsuragi, Blood Stalk attacks three of her students and uses his Steam Blade to turn one of them, a child named Takehiko, into an Ice Smash. Angered by Stalk's cruelty towards children, Sento transformed into Build NinninComic and attacked Stalk and the Ice Smash. Using Build NinninComic's 4Koma Ninpoutou's One Frame-Clone technique to split into two, Build fights Stalk while his clone brings the remaining two kids with Ryuga and Kyoka before fighting off the Ice Smash. After defeating the Smash and leaving Ryuga to extract the Smash element from Takehiko, the clone Build goes to assist the original Build. The two Builds fight Stalk until the clone disappeared, prompting Build to switch to his PandaGatling Trial Form. Stalk then combined his Steal Blade with his Transteam Gun to form the Steam Rifle before placing the Rocket bottle inside it to perform a Steam Attack, knocking Build out of his transformation and the Gatling Fullbottle out of the Build Driver. As Stalk went to retrieve the Gatling bottle, Ryuga attempted to attack him but Stalk simply knocked him aside. However, Ryuga reached the Gatling bottle first and used it to fire blue fireballs at Stalk. Ryuga then charges at Stalk and steals the Rocket Fullbottle from his rifle to give to Sento. Transformed into RocketPanda Best Match, Build attacks Stalk and overpowers him with a Vortex Finish Rider slash. Amused by Build's increase in strength, Stalk decides to leave a parting gift to Build and Ryuga and reveals to them that Takumi Katsuragi is the true founder Faust and the original creator of the Smash before leaving the scene via typhoportation.

Returning to Faust's lair, Blood Stalk is met by Gentoku Himuro, irritated with Stalk over the mess he caused in Hokuto. However, Stalk tells his partner that they are close to obtaining what they have been searching for, the research data of Takumi Katsuragi, with which they can use to upgrade the Rider system to a new level. The next day, Stalk followed Sento and Ryuga as they discovered the location of Katsuragi's research data, an abandoned Namba Heavy Industries Ltd. Integrated Sciences Laboratory. As the two retrieve a flash drive from a buried container, Stalk reveals himself and, commenting that he'd never thought Kyoka would hide her son's research in an abandoned building, knocks them aside and takes the flash drive. Sento then transforms into Build HawkGatling to fight Stalk, but Stalk receives backup when Night Rogue joins the fight and tells Stalk to let him deal with Build. While Night Rogue fights Build, Stalk attempts to exit but Ryuga attempts to attack him again. Ryuga attempts to punch Stalk but Stalk catches his fist and comments that his Hazard Level has risen to 2.4. Intrigued, Stalk decides to fight him for a while, tracking the rise in Ryuga's Hazard Level as they fight. After beating down Ryuga, Stalk hands him the driver and tells him he would like to see how Ryuga progresses before intervening in Rogue's battle with Build to give him and Ryuga a chance to escape. Pointing his Transteam Gun at Stalk, Night Rogue demands Stalk tell him what he's scheming, but Stalk tells him they don't need the driver, just the tools the data can create and that Sento and Ryuga can do it.

After discovering out Ryuga took Misora sightseeing outside nascita, Blood Stalk had Faust Guardians sent to their current location. He showed up as Ryuga was facing Night Rogue and Misora was passed out and told Rogue to not act behind his back. When Ryuga tried to flee with an unconscious Misora and fled, Night Rogue attempted to pursue him but was stopped by Stalk stopped him. Returning to Faust's lair, Stalk demanded Night Rogue to know why Rogue plotted behind his back. Rogue then informed Stalk that Faust's benefactor, Juzaburo Namba, president of Namba Heavy Industries Ltd. had asked to be given the Rider System and threatened to ally himself with either Hokuto or Seito if he did not receive it. As Rogue cancelled his transformation, Stalk asked Gentoku what he intended to do. Gentoku ultimately decided that they should steal the Pandora Box from the Touto Institute of Advanced Matter Physics in order to cause the three regions to declare war on each other.

Theft of the Pandora Box
The next day, Stalk and a squad of Faust Guardians waited in the garage level of the Touto Institute of Advanced Matter Physics. While Shingo Kuwata distracted Build, Eita Kawai disabled the security lock at the garage level, allowing Stalk and his Guardians to enter the Institute. Proceeding to the entrance floor, Stalk killed the four security officers stationed there by injecting them with a poison that disintegrated them. He then had Kawai trap the three Prime Ministers, Nariaki Utsumi, two security officers and the Pandora Box in an energy dome until he reached the floor where the box was located. Pursued by Touto Guardians and Touto Special forces, Stalk converted the Touto Guardians into Faust Guardians and went on his way. As he reached the eleventh floor, the dome dispersed, allowing Stalk to proceed toward the Pandora Box. He killed the two security officers with his poison before telling the Prime Minsters that he'll be taking the Pandora Box. Prime Minister Yoshiko Tajimi of Hokuto attempted to defy Stalk, but Stalk caused her to back down by threatening her with his Transteam Gun before using it to destroy the security cameras.

Making his way to the roof with the Pandora Box, Stalk was approached from behind by Ryuga, disguised as a Touto Security officer. Praising Ryuga for his boldness, Stalk had his Faust Guardians engaged Ryuga, but Ryuga defeated all of them with the power of his Dragon Fullbottle. Intrigued by Ryuga's power, Stalk attempted to fight him until Kawai showed up and told Stalk to leave Ryuga to him. Obliging his request, Stalk used his Steam Blade to infuse Kawai with Devil Steam and turn him into a Press Smash Hazard and leaving Ryuga to fight the Smash. On the rooftop, Stalk was confronted by Gentoku, who told Stalk the roof wasn't in their escape route. Stalk told him he was lost, Gentoku was unconvinced and commented on how Stalk had shot out the security cameras to cover his tracks. Transforming into Night Rogue, he demanded Stalk hand over the box, but Stalk refused. Rogue then engaged Stalk until Ryuga showed up and interrupted their fight. Stalk asked him what had happened to the Smash, to which Ryuga informed him that he beat it but couldn't extract the Smash element without an empty Bottle, surprising Rogue and impressing Stalk.

Ryuga then attacked Stalk, but was swiftly defeated due to the injuries he sustained from his previous fight with the Press Smash Hazard. Build HawkGatling then arrives to help him, prompting Rogue to assist Stalk against them. While Rogue fought Build, Stalk battled Ryuga. Stalk soon discovered that Ryuga's Hazard Level has risen to 3.0, and commended him for finally awakening his full power, though it still wasn't enough to beat him. As Stalk overpowered Ryuga, Build FireHedgehog ceased fighting Rogue and attacked Stalk. Rogue then used the opportunity to sneak-attack Build, giving Stalk the chance to insert his Cobra Fullbottle into his Steam Rifle and fire a Steam Shot at both Rogue and Build, knocking Rogue to a wall and cancelling Build's transformation as well as causing him to drop the majority of his Fullbottle collection. Stalk takes the Pandora Box and leaves.

Returning to the ground floor, Stalk finds the Press Smash Hazard and defeats it and extracts the Smash element from it, reverting it back to Kawai. As Stalk left, Kawai questioned Stalk if he was Takumi Katsuragi, suggesting that the Devil's Scientist had faked his death, but Stalk denies his claims. Kawai refused to believe him and stated that Katsuragi could've used modern technology to transfigure a corpse. Stalk then approached Kawai and demonstrated his ability to do so, painfully molding Kawai's face into Kuwata's. As Sento rushed to an unconscious Kawai, Stalk fused with a Faust Guardian Union State and fled. Pursued by Build RabbitTank, Stalk shot at Build to get him off his trail. However, Build managed to destroy one of the Union State's legs before finishing it off with the Machine Builder's axle saw, forcing Stalk out of the Union State.

Having overheard Stalk's conversation with Kawai, Sento questioned Stalk as to why he faked his death, framed Ryuga and injected Sento with the Nebula gas, but Stalk asked Sento if that's what he should really be asking. Sento then asked him why he created Faust, the Smash, and if the Rider System was a tool to protect the innocent. Stalk replied by knocking Sento down and telling him the Rider System was a military weapon for bloodshed, telling him science leads to destruction. Refusing to believe Stalk's claims, Sento states that if used properly, science can bring people happiness. Night Rogue then appears and knocks Sento out from behind. Having his Faust Guardians circle them and point their rifles at Stalk, Rogue questions Stalk about where he intended to take the Pandora Box. Stalk tells him that he was going to take it to their lair, offering Rogue the box. Taking the box, Rogue grabs Stalk to threaten him to not try a stunt like that again, before stealing the Rabbit, Tank and Lion bottle from an unconscious Sento. As Sento returned to consciousness, he grabbed Rogue's leg, demanded he return his bottles, but Rogue just kicks him in the face before walking away laughing.

Cover Blown
Because Gentoku refused to reveal the location of the Pandora Box due to Stalk's treachery, Stalk began searching for the box on his own, eventually tracking it to the Namba Heavy Industries Integrated Science Laboratory where he came across both Sento and Ryuga and Night Rogue. Stalk skirmished with all three of them before teleporting away with the Box.

After Gentoku disbanded Faust to cover his tracks, he discovered that Juzaburo Namba had dropped Gentoku as a partner and instead partnered up with Blood Stalk.

His identity as Soichi Isurugi was eventually discovered by Sento from Masahiro Nabeshima after he remembered who had approached him. Sento confronted Isurugi about this but Isurugi pointed out that Nabeshima could be lying. Sento thus came up with a secret plan to confirm Nabeshima's claim by having Misora purify the Octopus bottle in secret without Soichi knowing, which revealed that the reason Stalk was always aware of what Sento was doing was because Soichi knew about it. Isurugi appraised Sento for his plan, but Sento then demanded to Isurugi to hear from his own words that he is Blood Stalk. However, Isurugi simply fled out of nascita with Sento in pursuit.

Sento soon caught up to Isurugi and demanded to know what he was planning, why he had allowed Sento to become Kamen Rider Build and fight the Smash even though he was a part of Faust, but Isurugi simply told him it was all part of his plan. He then pulled out his Transteam Gun and Cobra Fullbottle and transformed into Blood Stalk to engage Sento, who transformed into Build OctopusLight. Stalk succeeded in beating Build down and knocking him out of his transformation, allowing him to obtain the Octopus and Light Fullbottles. Now in possession of the Pandora Box, the green Pandora Panels and the Touto bottles, Stalk bids farewell to Sento and leaves the scene. The next day, Isurugi gave the Box, green Pandora Panels and twenty Touto Fullbottles to Juzaburo Namba. However, after Namba placed the Rabbit bottle in one of the green panels, the two discovered that Fullbottles they had were fakes and that Sento had swapped them for the real ones. Wanting to settle things before he brought his plan to its next stage, Stalk called Sento and arranged with him to meet in the alleyway where Isurugi had first found Sento.

As it rained, Sento came across Soichi in the alleyway with the Pandora Box. Sento asked Isurugi if the time they had spent together was all a lie, to which Soichi replied that not all of it was a lie and it had made him feel somewhat bad for deceiving Sento. Sento then sets down the umbrella he was using to shield himself from the rain and inserts the Rabbit and Tank Bottles into the Build Driver to transform into Kamen Rider Build, while Soichi draws out his Transteam Gun and inserts the Cobra Fullbottle into it to transform into Blood Stalk. The two engage each other in a fight that leads to an abandoned construction warehouse. However, recalling his memories with Soichi, Sento stops giving Stalk an opportunity to beat him down and force him out of his transformation. Sento confesses that he can't kill Stalk but Stalk coldly tells him that the battle is over and points his Transteam Gun at Sento. However, Ryuga then arrives and knocks the gun out of his hand with his Beat Closer.

Transforming into Kamen Rider Cross-Z, Ryuga brutally assaults Stalk, angry at how he manipulated Sento and Misora. Retrieving his Transteam Gun, Stalk inserts the Cobra Fullbottle into it to perform a Steam Break shot that knocks Cross-Z back and cancels his transformation. As Sento rushes to Ryuga, Stalk mocks him for not finding it strange that he was the one who rescued Misora and that he was the one who asked him to become Kamen Rider Build to fight the Smash, revealing that it was all part of his scheme to give Misora a hero to motivate her to purify Fullbottles again. Stalk mocks Sento and Ryuga as being puppets but Sento tells him that he and Ryuga aren't puppets because they still fight to protect people. Sento then reveals his newest creation, the RabbitTank Sparkling Bottle, which he uses to transform into Kamen Rider Build RabbitTank Sparkling. Build RabbitTank Sparkling then overpowers Blood Stalk and finishes him off with a Sparkling Finish Rider Kick, sending Stalk flying. His transformation cancelled, Soichi appraises Sento and reveals to him and Ryuga that Gentoku is Night Rogue. He tells them that he will allow them to keep the Green Panels and the Pandora Box, as he can take them back at any time, before bidding them farewell and leaving.

Rebuilding Faust
Watching from the shadows, Stalk as Soichi observed Sento and Ryuga when they approached Gentoku as part of a plan to expose his identity as Night Rogue, the leader of Faust. After Ryuga's temper ruined their plan and the two left, "Soichi" approached Gentoku and convinced him to set up a trap for Sento and Ryuga to bring the Pandora Box to the hospital where Taizan was. After having his father contact Sento, Gentoku informed Stalk that the Riders had fallen into their trap.

While Sento and Ryuga took the bait, Stalk as Soichi snuck into nascita and copied the schematics for the Sclash Driver on a USB drive. Before he could leave though he ran into Misora, who demanded to know where he'd been. "Soichi" told her that he'd been cultivating his own coffee beans, a lie Misora seemed to buy into. Before leaving, "Soichi" told Misora that because he was going even more busy from now on, he would have no time for him to see her and asked her to say "hi" to Sento and Ryuga for him.

After Build and Cross-Z escaped with the Pandora Box, Gentoku confronted Stalk in the Touto government office. Gentoku demanded to know why he wasn't at the hospital during the trap, but Stalk simply presented him the coffee beans and said he had important business. Angered by Stalk's defiance, Gentoku throws Stalk's beans to the ground before grabbing Stalk by Soichi's jacket and demanding to know if he'd been deceiving him. Acting shocked, Stalk told Gentoku to let go of his jacket, as it was his favorite, and assures him not to worry. Stalk then reveals Sento's true origins to Gentoku.

Following Gentoku's apparent dismantling of the organization, Blood Stalk moved Faust to Hokuto and was employed by their government to develop new weapons for them to use in their invasion of Touto. Thus, Stalk and Faust provided them with the resources they needed to engineer Smash and the schematics for the Sclash Driver, allowing them to to create Kamen Riders. With former farm owner Kazumi Sawatari as their test subject, Blood Stalk and Faust used him to create Kamen Rider Grease. They also developed a new form of Smash called Hard Smash, who were capable of retaining their consciousness in their Smash transformation. Stalk and Faust turned three farm workers of Kazumi's into Hard Smash, and they would come to be known as the Hokuto Three Crows.

Working with Namba
Stalk later switched over to working with Seito when they invaded and conquered Hokuto with backing from Namba Heavy Industries Ltd. When a now banished Gentoku Himuro was chained up in a Namba Industries compound after arriving in Seito and demanding to be made a Kamen Rider, Stalk approached him and offered to make him into a Kamen Rider. While they already had a candidate for the Kamen Rider of Seito, the candidate was unable to transform using the Sclash Driver and Stalk admitted to Utsumi that Gentoku had one thing their current candidate did not: a drive to become more powerful.

After him and Utsumi discovered Gentoku had murdered their top candidate, Stalk gleefully informed Gentoku that he was now their top candidate for Kamen Rider and began putting him through rigorous training to raise his Hazard Level to the point where he could use the Sclash Driver. Said training involved having Gentoku be beaten down by Guardians until he transformed into a Kamen Rider and fought them off. Once Gentoku had successfully transformed into a Kamen Rider, Stalk and Namba deployed him in the war against Touto as the Kamen Rider of Seito.

After Seito lost a proxy battle with Touto and thus had to relinquish the Fullbottles and Pandora Box as per their agreement, Blood Stalk was summoned by Namba to kill Seito's Prime Minister Masakuni Mido and swap their faces so Namba could take control of Seito.

Becoming Evol
Stalk later kidnapped Touto Prime Minister Taizan Himuro and attempted to get Sento and Ryuga to hand over the Evol Driver so he could regain his long lost power. The two were ready to deliver the Driver to Stalk, but chose not to and fought off Stalk with assistance from Kamen Rider Rogue. After being soundly defeated by the Riders, Stalk attempted to retreat but was chased down and knocked out of his transformation by Rogue. However, thanks to the actions of Nariaki Utsumi, Evolt managed to gain the Evol Driver and transform into Kamen Rider Evol. Overpowering Rogue, Evol prepared to finish Gentoku off but his attack was blocked by Gentoku's father Taizan.

Completing the Pandora Box


"The time is finally here. Taste the despair!"

- Evol as he constructs the Pandora Tower.

Eventually, Evol possesses Ryuga and obtains all of the panels of the Pandora Box and uses them to assemble it and use it to create the Pandora Tower to destroy Earth. Horrified, Juzaburo Namba sends Nariaki Utsumi out to go stop him, but Evol simply shoots him away with the Nebulasteam Gun. He then laughs as the Pandora Tower is completed, declaring that "Earth is finished".

Evol then uses the Pandora Box to create the Evol Trigger, the device that allowed him to destroy Mars, but discovers that the body of Ryuga is not strong enough to use it. He is then ambushed by Vernage possessing Misora, who knocks him against a wall before teleporting away with Sento and the Pandora Box. She then explains to Sento, Kazumi and Gentoku who Evolt is and how he annihilated all life on Mars.

Back at Seito's capital, Evol claims to Namba and Utsumi that he created the Pandora Tower to showcase Namba's power to the world. Though unnerved, Namba goes along with Evol's explanation. Evol is later seen in Ryuga's body leading a Seito on Touto before Build steps in to fight him. Transforming into Evol Dragon, Evol and Build fight, and Evol reveals to Build that the whole point of Project Build was to create someone strong enough to harness the energy of the Evol Trigger. Discovering that Build has raised his power to superhuman levels, Evol abandons Ryuga as a host and tries to possess Sento, but Sento reveals this was his plan all along and attempts to kill both Evol and himself by rapidly raising his Hazard Level until he overclocks. However, Sento's plan fails and Evol succeeds in claiming Sento as a host, much to Ryuga's horror when he wakes up.

Possessing Sento
Ryuga attempts to transform into Kamen Rider Cross-Z to fight Evol Rabbit, but Evol reveals that he removed all of his alien DNA from Ryuga's body when he exited it and that without it, he cannot transform into a Kamen Rider. Kamen Rider Grease then tries to attack Evol, but Evol effortlessly beats him down and cancels his transformation before leaving. Meeting with Namba, Evol reveals his true origins to the war profiteer, but claims he only wants to regain his former power.

Evolt later arranges a meeting with Ryuga Banjou and Kazumi Sawatari, promising to return Sento to them if they hand over the Pandora Box. At the meeting spot, Evolt notices that he is being accompanied by Engine Bro's and Remocon Bro's, who were sent by Namba to keep an eye on him. After Ryuga and Kazumi arrive, Evolt reveals that he has no intention of letting Sento go, as revenge for him impeding the progress of his plans. He leaves the two to be fought by the two Kaisers, not considering them worthy of being taken care of by himself, though he does interfere in the battle when Grease starts to gain the upper hand.

However, after Kamen Rider Rogue appears and defeats Remocon Bro's and Engine Bro's, Evolt decides to enter the battle himself. Transforming into Evol Cobra, Evol engages Rogue and manages to overpower him after switching to Evol Rabbit. During the battle, unknown to Evol, Ryuga managed to snatch the Dragon Fullbottle off of Evol's belt. He then attacks Evol un-transformed and somehow manages to inflict damage upon him. Shocked, Evol questions how he is able to do that without his DNA inside of him. Ryuga then uses the Dragon Fullbottle to transform into Cross-Z and then Cross-Z Magma before engaging Evol alongside Kamen Riders Grease and Rogue. The three combine their energies for a final attack against the Kamen Rider, but Evol manages to absorb their energies and use them to transform into his final form, Evol Black Hole, setting Sento free in the process.

Black Hole


"Phase 4... complete!"

- Evolt after assuming his Black Hole form.

Assuming his true form, Evol congratulates the Kamen Riders on helping him re-achieve his true powers, declaring that nothing can stop him now. The three Kamen Riders then attack Evol but he effortlessly fights them all off, forcing them to retreat back to nascita.

Taking the form of Soichi Isurugi, Evolt approaches Namba and declares that he will supplant Namba Heavy Industries as Seito's ruler, though offers to let him keep his spot as Prime Minister. Namba refuses, but Evolt decides to give him a day to think it over. He later approaches Nariaki Utsumi and proposes that he come work for him, complimenting his skills as a scientist. He then reveals to Utsumi a second Evol Driver.

The next day, Evolt is approached by Nariaki Utsumi, Remocon and Engine Bro's and a squad of Hard Guardians. Utsumi pulls out a tablet and from it, Namba declares his refusal to go along with Evolt's plans. Unfazed, Evolt assumes his form as Black Hole and teleports everyone present to a barren battlefield for them to fight at. The Hard Guardians all charge at Evol, but the alien destroys them all at once with only a fraction of his power. The Washio brothers then try attacking Evol, but they fair little better and are easily beaten down. However, backup soon arrives in the form of Kamen Riders Build, Cross-Z, Grease and Rogue, who all attempt to take on Evol again. Despite the best efforts of the Riders and Kaisers, Evol proves too powerful for them and eventually announces his intention to finish things, using his Black Hole finisher to kill Rai Washio.

Using his brother's Fullbottle to assume Hell Bro's, Fu Washio charges at Evol in a fierce attack to take him down, which fails. Before he can be killed however he is saved by Cross-Z Magma, who attempts to fight off Evol to little success. Forcing Ryuga out of his transformation, Evol prepares to finish him off, but Ryuga is pushed out of the way at the last second by Hell Bro's, who absorbs the attack instead. Forced out of his transformation by the attack, Fu Washio also dies, but not before proclaiming how nice it was to fight for someone else's sake.

Evol then opens a portal to Juzaburo Namba's office and goes to kill him. Namba pleads for Evol to spare his life, offering up his company to him if he lets him live. Amused by Namba's cowardice, Evol declares that he loves how disgusting humans are and gives Namba a hug, only for him to kill Namba right afterword by causing him to disintegrate.

Evol then returns to the battlefield and restates his offer to Nariaki Utsumi, tossing him Namba's cane. Believing that since Namba is dead now nothing matters, Utsumi accepts Evol's offer, causing Evol to laugh and declare that he doesn't even want to destroy Earth anymore. Evol tosses Utsumi the second Evol Driver and Utsumi uses it to transform into a Kamen Rider, with Evol declaring him to be "Kamen Rider Mad Rogue".

Final Plan
Back at the Pandora Tower, Evol informs Utsumi that he will be assuming the identity of Masakuni Mido now that Namba's dead and that they will be seizing control of Touto and reuniting Japan, stating that it will make things easier in the long run. Utsumi then asks Evol what he intends to do about the Kamen Riders, to which Evol replies that he intends to still keep on using them to further his goals, instructing Utsumi to bring them to him alive. Admiring his Evol Driver, Utsumi inquires to Evol where the second one came from, as he had previously believed their to only be one, but Evol coldly warns him to keep his questions to himself.

After Mad Rogue was defeated by Build Genius Form, Evolt arrived and noted he was previously unaware of the existence of the Genius Bottle before punching Kazumi, stealing the Hokuto Three Crows' Lost Bottles from him and teleporting away with Mad Rogue. Back at Faust's lab, Evolt reveals to Utsumi that he intends to use the Lost Bottles to turn humanity into the final form of Smash, Lost Smash, and have rampage and destroy each other. Utsumi then asks if this is why Evolt left the Kamen Riders alive, to which Evolt confirms his suspicions, commenting that he thinks they would make good Lost Smash.

Later, after Mad Rogue and Owl Lost Smash were defeated by Kamen Rider Build Genius Form and Grease, Kamen Rider Evol showed up in his Cobra Form to claim Kiba's Lost Bottle, stating that he intends to use it to create a new world. Evol then attacks and fights Build. After getting beat back by Build, Evol attempts to shift to his Black Hole form, but is stopped by Build, who proceeds to knock Evol out of his transformation. Complimenting Sento on the Genius Fullbottle, Evolt flees the scene to go back to Faust's base.

After Sento arranges a meeting with Shimizu Kyouichi, the first Strong Smash, Evol has Shimizu turn into a Lost Smash and attack Sento. After Build reverts him back to his original state with his Genius Form, Evol shows up as Black Hole Evol and kills Shimizu to keep him from providing Sento with any information, mocking Sento for being unable to save him. Evol Black Hole and Build Genius Form then fight, with Build managing to overpower Evol and beat him down with his Genius Finish. Proclaiming that he now understands the human emotion of anger, Evol fiercely attacks Build but is unable to do anything to his Genius Form. Evol then decides to just take the Fullbottles he's recovered and leave to go back to Faust's lab base.

Back at the base, Evolt converses with Shinobu Katsuragi, who notes that Evolt was acting more emotional than he usually does in his fight with Build. Evolt then informs Shinobu that they will have to speed up their timetable for their plans. As Shinobu completes another Lost Bottle, Evolt comments that they only have four more Bottles to go before they can "create a new world". Shinobu then asks Evolt why he killed Shimizu, as he was the last candidate they had to become a Lost Smash, to which Evolt informs him that Shimizu was spilling too much about their plans, and that they can use the Kamen Riders to create Lost Smash. Utsumi then walks in and Evolt tells him to speed up the production of Lost Smash before remarking that he has "a nation to unite".

Kamen Rider Prime Rogue
Evolt appears as the main antagonist of the Hyper Battle DVD special. As Kamen Rider Evol, Evolt and two Hard Guardians mount an attack on Touto while Gentoku Himuro and Misora Isurugi are out shopping for clothes. Sento becomes Kamen Rider Build RabbitRabbit to fend him off, destroying the two Hard Guardians before facing off against Evol. But before he can use the Genius Fullbottle to transform into Kamen Rider Build, Evol grabs it and pulls a cloth over it, allowing him to swap it out for a regular metal can. Without the Genius Bottle, Build is able to do little against Evol who overpowers him and knocks him out of transformation. With Sento too injured to do anything, Misora grabs the Build Driver and attempts to use it but before she can do so Gentoku takes it from her and places it on himself. Inserting the Prime Rogue Fullbottle into it, Gentoku transforms into Kamen Rider Prime Rogue to match up to Kamen Rider Evol. Though beating back Evol at first, Evol manages to gain the upper hand and overpower Prime Rogue until Rogue is spurred on to continue fighting by the encouragement of a child he met earlier. Rogue and Evol then charge at each other and use their finishers, with Rogue overpowering Evol and knocking him to the ground with his Prime Scrap Finish. Beaten back, Evol says "Ciao" to the Riders before exiting.

Conquering Japan
Black Hole Evol then leads an attack on the Touto government office along with Kamen Rider Mad Rogue. While Mad Rogue and a pair of Hard Guardians fought Kamen Riders Cross-Z Magma and Grease, Evol faced off against Sento and Gentoku. Sento angrily asked Evol where his father was, but Evol pretended not to know. After fighting off Build Genius Form and Kamen Rider Rogue, Evol generated a black hole and used it to annihilate the Touto government office before departing along with Mad Rogue.

As Seito occupied Touto's territories, Evolt disguised himself as Masakuni Mido and gave a speech that was broadcasted across Touto, Hokuto and Seito, where he declared that he would unite the three territories and build a new Japan. After his speech is finished, Evolt tells Utsumi to procure the Kamen Riders so they can create Lost Smash from them. However, Utsumi points out that mass-producing Lost Smash and having them attack people would trigger the downfall of the nation and questions Evolt as to what he really wants, but Evolt tells Utsumi not to ask anymore questions about stuff he's not ready to know yet if he values his life.

Completing the Black Pandora Panel
After Utsumi was defeated by Kamen Riders Build Genius Form and Rogue, Evolt showed up along with Shinobu Katsuragi and revealed to the Riders that Shinobu had manipulated Sento and Ryuga into becoming Kamen Riders. Evolt then teleported away through a black hole with Utsumi, leaving Shinobu to fight the Riders.

Evolt later kidnapped Misora Isurugi so Shinobu could turn her into the CD Lost Smash by subjecting her to a high level of Nebula Gas. The CD Lost Smash was then released to fight Kamen Rider Build by Shinobu.

After Shinobu returned to Faust's base in Hokuto after being beaten by Build Genius Form and Cross-Z Magma, Evolt commented on how that was the first time he was wrong, to which Shinobu admits that he overestimated them. The two are then alerted by Nariaki Utsumi that Gentoku and Kazumi are attempting to infiltrate their base, to which Evolt states that "there's more fun to be had".

After Gentoku and Kazumi escape with help from Build and Cross-Z Magma, Evolt notes to Shinobu that he let them get away again, to which Shinobu replies by commenting on how strong they are. Later, Evolt calls Sento and tells him to hand over the Lost Bottle he retrieved from the CD Lost Smash, threatening to harm his family and friends if he refused.

Sento then goes to meet Black Hole Evol, but refuses to hand over the Lost Bottle. Ryuga, Kazumi and Gentoku then arrive to back up Sento, having tracked his position using a transmitter. The four then transform into their Kamen Rider forms and engage Black Hole Evol. Evol at first easily beats them down, but the Kamen Riders manage to gain the upper hand by having Rogue and Grease hold Evol while Cross-Z Magma disables the Evol Trigger, reverting Evol back to his Evol Cobra form. Build Genius Form then uses his Genius Finish on Evol and finishes off the evil Kamen Rider. Commenting that the Riders' fighting skills are "not bad", Evol tells the Riders that their fight is not over yet before exploding and seemingly dying, leaving behind three Lost Bottles. Shinobu as Build HawkGatling then swoops in and collects the Lost Bottles, telling the Riders that everything has gone exactly as he planned.

Return
Placing the Evol Driver inside a metal container to prevent Evolt from regenerating from the DNA he has inside it, Shinobu Katsuragi reveals that he was planning to stop Evolt all along, and only helped him out in order to complete the Black Pandora Panel, which would allow for warp travel between worlds. He states that Evolt sought to complete the panel because he could use it to making traveling from planet to planet easier and less time consuming.

Nariaki Utsumi then walks in and is revealed to be possessed by Evolt, who anticipated that Shinobu would betray him and sent some of his essence to possess Utsumi right before he was defeated. Evolt then kills Shinobu before transforming into Kamen Rider Mad Rogue with Utsumi's Evol-Driver and fighting Kamen Riders Cross-Z Magma, Grease and Rogue while Sento rushes over to his father. After fighting the Riders for a bit, Evolt remarks that Mad Rogue is limiting for him due to being fitted for a human, and discards Utsumi as a host before retrieving the Evol-Driver from the metal container and using it to transform into Kamen Rider Evol Cobra. Evol then retrieves the Black Pandora Panel and fights off the Kamen Riders, prompting them to retreat. Glancing at the panel, Evol remarks that he only needs one more Lost Fullbottle to complete it.

Later, as Masakuni Mido, Evolt implements a new form of government in Japan where Touto, Hokuto and Seito will each have regional governors and which will be based out of the Pandora Tower. He then stages an attack by Flying Clone Smash in order to lure out the Kamen Riders, save for Kazumi, who was injured in his last battle with Evolt.

Achieving his Complete Form
Confronting the Riders atop a rooftop, Evolt faces off against Sento, who attempts to use the Genius Bottle to transform into Build Genius Form, but finds he is unable to use it. Evolt reveals that he infected Kazumi with his DNA from his Evol Trigger in order to retrieve the last Lost Bottle. He has Kazumi get up, shock Misora and Sawa, before bringing him the CD Lost Bottle and Evol-Trigger. After transforming into Black Hole Evol, Evol places the final Lost Bottle in the Black Pandora Panel and absorbs it to achieve his true form.

After easily defeating Kamen Riders Cross-Z Magma, Grease and Rogue, as well as demolishing several buildings in the process, Evolt grabs Sento and warps the two of them to an unnamed planet. where he announces his intention to destroy every planet in the universe. He then creates a massive Black Hole and uses it to annihilate the planet and all of its inhabitants, leaving him and Sento stranded out in space before he warps them both back to Earth.

However, Sento realizes that the Genius Bottle is powered by hope and not anger, and uses that to use it to transform into Kamen Rider Build Genius Form. Build Genius Form, Cross-Z Magma, Grease and Rogue then all Rider Kick Evolt at the same time in order to force the Black Pandora Panel out of him. Evolt grabs the Black Pandora Panel before the heroes can claim it, but Sento punches him with the Hazard Trigger, knocking him out of his complete form and purifying two of Lost Bottles as well as knocking them out of the Black Pandora Panel. Evol attempts to grab the two Lost Bottles, but Cross-Z Magma snatches them up. Evol then opts to retreat rather than stay around any longer.

Back at the tower, Evol watches a news report announcing the governors for the three regions (who are all secretly members of the Blood Tribe). Utsumi then walks in and accuses Evol of not being interested in ruling Japan at all and instead wanting to buy time in order to complete the Black Pandora Panel. Evol responds by grabbing Utsumi by the throat and threatening him to not reveal his true plans to the Kamen Riders.

Kamen Rider Build: Be The One
Evolt appears as the overarching antagonist of the movie Kamen Rider Build: Be The One. He met with the three new governors of the regions of Japan who are really, along with himself, the last surviving members of the planet-devouring extraterrestrial clan known as the Blood Tribe possessing the other members of the Mars expedition: Kengo Ino, Ryoka Saiga and Mitsuomi Gohara, as well as the ones responsible for manipulating the three regions of Japan into waging war with one another. The three state they intend to finish what Evolt started and consume the planet, to which Evolt tells them that he will not interfere with what they do, but reminds them that he has the upper hand with the power of the Pandora Box.

At the end of the movie, after his fellow Blood Tribe members have been defeated by the Kamen Riders, Evolt shows up to collect their Lost Bottles.

Challenge to the Kamen Riders
Following the events of Kamen Rider Build: Be The One, Evolt makes an announcement to the entirety Japan where he reveals himself as a being of extraterrestrial origin and declares his intentions to destroy the world. He goes on to challenge the Kamen Riders to a final battle to decide the fate of the planet and tells them to meet him at the summit of the Pandora Tower and to bring the Lost Bottles.

In preparation for the battle, Evol practiced fighting a simulation of a Strong Smash Hazard and a Stretch Smash Hazard, easily destroying both with only a single strike. He then remarks to Utsumi that he's making a good replacement for Shinobu.

On the day of the final battle, a crowd of people, including news reporters, has gathered around the Pandora Tower in order to witness the fight. To get them to back away from the Tower, Evolt flings a helicopter near them. Sento, Ryuga, Kazumi and Gentoku then arrive right before Evolt makes his entrance, accompanied by a battalion of Hard Guardians. Evolt proceeds to explain to the four the rules: they will have to make it to the top of the tower, and for every ten minutes that they aren't up there, he will destroy a section of Japan with one of his black holes. Evolt then teleports off to the top of the tower and leaves his Hard Guardian army to fight the Riders. Transforming into their Kamen Rider forms, the four combine their attacks to destroy the entire army, before smashing a hole in the Tower and making their way inside.

At the top of the tower, Evolt decides to make things interesting and, reverting to his Evol Cobra form, sends off a fraction of his DNA to assume the forms of the Hokuto Three Crows in order to mess with Kazumi. Upon seeing the three alive once again, Kazumi instantly identifies them as fakes. Complimenting that he's impressed he caught on, Evolt tells the Riders to keep moving before he destroys another section of Japan. Telling the other Riders to go along without him, Grease stays behind to take on the mimics of the Hokuto Three Crows.

While fighting some regular Guardians and Hard Guardians, the other Riders briefly contemplate going back to help Grease, right before Evolt destroys another section of Japan, causing them to realize they have to move on.

After Kazumi transforms into Kamen Rider Grease Blizzard using the second Build Driver recovered from Shinobu Katsuragi, Evolt watched from atop the Pandora Tower, remarking that he "had gotten all dressed up to die." Evolt later sent out clones of Remocon Bro's and Engine Bro's to challenge the Riders. Kamen Rider Rogue opts to stay behind to fight them, telling Build and Cross-Z Magma to go on ahead. Initially being overpowered by both of them, Rogue soon receives assistance when Mad Rogue shows up and reveals he was working against Evolt the entire time. The two then fight the clones, who merge together to form clone Hell Bro's. They manage to finish the clone off by combining their powers, destroying it and causing it to drop the Hammer Lost Bottle.

Evol Cobra himself then shows up to claim the Lost Bottle and attacks the two Riders. Mad Rogue then reveals he is able to use Evolt's phases thanks to him collecting some of Evolt's DNA and fights the evil Rider one-on-one, only to be defeated and have his transformation canceled thanks to his body shortening out. Evolt then reveals to Gentoku and Sawa, who had showed up to deliver the Pandora Box panels, that Utsumi had to be turned into a cyborg after Gentoku shot him off a cliff due to him being heavily injured. In a rage, Rogue attacks Evol Cobra, only to be overpowered and knocked out of his transformation. Evol then attempts to finish them off with the Steam Blade, but before he can strike them Utsumi gets up to block the attack, dying to protect the Lost Bottle. Gentoku then uses the chance to teleport himself and Sawa away.

Meanwhile, Kamen Rider Grease overpowers and beats down Evolt's clones of the Hokuto Three Crows, managing to destroy all three of them. However, using the Blizzard Knuckle to transform causes Kazumi to begin to die. Not being able to prevent his demise, Kazumi uses this as an opportunity to purify the Castle Lost Bottle for Sento, which he hands to Misora as he dies in her arms.

As Evolt annihilates another section of Japan with a black hole, the remaining Riders and Sawa reach the top of the Pandora Tower and begin treating their wounds. Misora then shows up to deliver the news the Kazumi is dead. As the five all grieve, Evolt shows up to confront them. Looking straight at him, Sento screams "Evolt!"

Battle Atop the Pandora Tower
After mocking Sento and co. for their humanity, Evolt transforms into Kamen Rider Evol Black Hole and does battle with the three remaining Kamen Riders, Build, Cross-Z Magma and Rogue. Evol easily manages to overpower the three Riders and obtain the two Lost Bottles he needed to become his final form. After transforming into his monster form, Evol beats down the three Riders again and knocks Sento and Ryuga out of their transformations. He then creates a massive black hole over the Earth and uses it to begin consuming the Earth, destroying the Moon in the process and allowing Evolt to assume his ultimate form. However, Evolt opts to drag out the destruction of Earth for a bit so he can witness the despair on Sento and Ryuga's faces for a bit longer.

Despite his injuries, Rogue refused to go down and charged at Evolt to attack him all by himself. Despite Rogue's best efforts, he was unable to do any damage against Evolt and was overwhelmed by the alien's power, having part of his faceplate shattered in the process. Thus, Gentoku instead opted to go for the Evol Trigger, the source of Evolt's power. He succeeds in damaging it, but Evolt fatally injures him soon after and knocks him out of his transformation, causing him to die and fade away.

Inspired on by Rogue's courage and the cheers of the people at the surface of the Pandora Tower, Sento and Ryuga got up and transformed into Kamen Rider Build Genius Form and Cross-Z Magma in spite of their injuries to take on Evolt. Evolt attempted to fight them, but the damage done to the Evol Trigger by Gentoku caused him to become paralyzed, granting Build an opportunity to attack him. Using the Genius Finish, Build manages to force the Black Pandora Panel out of Evolt, which Ryuga then grabs and combines with the White Pandora Panel, causing the black panel to be destroyed. Misora then rushes out to give the Riders the other Pandora Panels so Build can combine the White Pandora Panel with then. Placing the White Pandora Panel with the other panels, Build begins merging their Earth with an alternate universe Earth that has no Skywall.

To complete the merger of worlds, Build attempts to use Evolt's energy to power it, but Cross-Z Magma steps in and cancels Build's transformation to do it instead, as he has Evolt's DNA. Grabbing Evolt, Cross-Z Magma flies into space with him and into a dimensional rift between the two worlds, granting the fusion enough power for it to finish.

Final Battle
However, Sento flies into the rift after Ryuga in order to rescue him. He finds Ryuga lying on the ground, though it turns out to really be Evolt in disguise. Evolt then reveals that since he has survived, the merger will cause the two worlds to collide and destroy each other unless he can be defeated. Transforming into Build RabbitRabbit, Sento fights Evolt in his ultimate form and is quickly overwhelmed and knocked out of his transformation. Assuming the form of Soichi Isurugi, Evolt mocks Sento and tells him he is nothing more than a "sham hero" he created. Sento responds by rejecting this, claiming that Build was created and built up by his friends. Evolt then reverts back to his ultimate form and prepares to finish Sento off, but is stopped by Ryuga resisting him from the inside. Ryuga gives Sento some words of encouragement, telling him that his friends all believe in him, before Evolt fully consumes him and spits out the Dragon Fullbottle.

Sento then transforms into Build RabbitRabbit and fights Evolt again. As the two battle, both begin to fade, causing Evolt to question which one of them will die first. Sento later switches to Build TankTank after being overpowered as Build RabbitRabbit, and later again to Build Sparkling form which he uses to destroy Evolt's Evolti Graspers and Evolti Blasters before eventually being knocked out of that form and back to his base form as Build RabbitTank. With both down to their base Build uses the Rabbit and Dragon Fullbottles to transform into Build RabbitDragon and uses his finishing move on Evolt. Evolt attempts to stand his ground, but is ultimately overpowered by Build and destroyed with his energy being used to complete the fusion of the two worlds, thus creating a world where he never existed and where the Skywall Disaster never happened. With that, Evolt's reign of terror was brought to a definitive end.

Kamen Rider Build: Final Stage
However, it's revealed in the stage show that Evolt managed to survive by liquifying some of his genes, preventing the two Earths from merging and making it so they would be destroyed instead. Evolt soon finds Sento and Banjo still in the crevice of light and tells them that if they want to escape the crevice they have to collect the ten Lost Bottles and place them in the White Pandora Panel. However, Sento sees through Evolt's deception and points out that doing so would revive Evolt. Evolt compliments Sento for being clever and affirms Sento's suspicions, but states that in order for his energy to be used to complete the merging and creation of the New World, he will have to be defeated at full power.

Eventually, will help from a revived Grease, Rogue and Mad Rogue, Build and Cross-Z were able to collect all ten Lost Bottles and place them in the Pandora Panel, reviving Evolt. Upon being brought back, Evolt assumes his Kamen Rider Evol Black Hole form and summons DNA copies of his form as Blood Stalk and two Hard Guardians to fight Grease, Rogue and Mad Rogue while he battles Build and Cross-Z. Cross-Z attempts to defeat Evolt by destroying his Evol Trigger, but Evolt reveals that both the Evol Driver and Evol Trigger are dummies and that he no longer needs them now that he has his complete form.

However, the Kamen Riders manage to regain enough power to assume each of their most powerful forms (Genius for Build, Cross-Z Magma for Cross-Z, Grease Blizzard for Grease, Prime Rogue for Rogue) and, with the encouragement of the audience are able to defeat Evolt's DNA copies. Evolt then reveals his ultimate form, a white, Genius Bottle version of his Feverflow Ultimate State, and decides to start taking the battle seriously. Evolt initially easily overpowers all of the Riders with his tremendous might, but Build and Cross-Z manage to match up to him by merging to become Cross-Z Build once again. Evolt then battles Cross-Z Build in a climactic battle and is defeated by the Kamen Rider. As a final act of spite, Evolt attempts to disperse his genes to allow himself to reform once again, but Build uses the Genius Bottle to turn them into Lost Smash, allowing the Riders to finally destroy them. Cross-Z Build then finishes of Evolt, who comments that it would be a miracle for him to see the New World through to its end before dying and exploding.

Kamen Rider Build NEW WORLD: Kamen Rider Cross-Z
Some time after Evolt's demise, Evolt's older brother Killbus, the king of the Blood Tribe, came to Earth searching for Ryuga Banjou. Despite having seemingly perished in his final duel with Sento Kiryu, Evolt managed to ensure his return by attaching a piece of himself to Ryuga.

When Killbus beat down Ryuga, Evolt re-emerged as Blood Stalk and fought off his brother before grabbing the Pandora panels from him and teleporting away to a safe place with Ryuga and Yui Mabuchi. While Yui was resting, Stalk explained to Ryuga the history of his people, the Blood Tribe, and how his brother Killbus, the king of the Blood Tribe, annihilated their homeworld Planet Blood and sent the remaining members off to destroy more planets, with Evolt grabbing the Pandora Box right before Planet Blood was destroyed. Stalk then re-enters Banjou to recuperate his strength just a Yui wakes up.

After building back up his power, Stalk sets up a Faust backup lair so they can devise a plan to defeat Killbus, but Killbus tracks them down and attacks them, revealing his new Kamen Rider form as Kamen Rider Killbus. Killbus snatches the White Pandora Panel from them and turning it into a device to use to become more powerful so he can destroy the world. After Ryuga transforms into Cross-Z Charge, Stalk and him face off against Killbus, but Killbus overpowers both of them and fatally wounds Stalk with his finisher. Letting out a final "ciao", Stalk tosses Ryuga one of the Cross-Z Fullbottles before perishing. However, this was not the end of Evolt.

Recognizing that Evolt would be a valuable ally against Killbus, Sento Kiryu managed to bring him back from the DNA he had infused into Ryuga, now in his form as Kamen Rider Evol. Evol stowed away inside Ryuga as the Riders went to confront Killbus and re-emerged to face his brother alongside Ryuga after he transformed into Cross-Z Magma. Cross-Z Magma and Evol fought Killbus together but even with their combined power they were unable to overcome the Blood Tribe King. Killbus knocked Ryuga out of his transformation and critically wounded Evol, but before he could do anything more, Yui showed up with the Muscle Galaxy Fullbottle. Ryuga attempted to transform with it but to no avail, causing Evol to get up and, proclaiming his brother was right, asking Killbus if he could join him in his universe-wide rampage. Evol then grabbed Yui and began choking her in order to make Ryuga determined enough to be able to transform. As Ryuga successfully activated the Muscle Galaxy Fullbottle, Evolt merged with him as he was transforming with it, causing both of them to fuse together and transform into Kamen Rider Cross-Z.

Even with their newfound strength, the two Riders were unable to overpower Killbus at first. However, remembering the times he spent with Sento and his friends, Ryuga gains the determination to overcome Killbus. After beating Killbus down with several powerful attacks, Cross-Z Evol finishes Killbus off with their finisher, with Evol gloating to his brother just before he finished him off.

Some time later, with Killbus dead, Evolt emerged out of Ryuga once more, now in his Feverflow mode. Ryuga questions if Evolt only pretended to betray him in order to make him strong enough to use the Muscle Galaxy Fullbottle, to which Evolt responds that there is "no need to thank [him]". Evolt then states he will be leaving Earth for now and will return once he's gotten stronger, bidding Ryuga a final "ciao" before heading off into space to parts unknown.

Personality
Blood Stalk displays a disturbingly flippant demeanor, casually carrying out his duties as a Faust strategist and enforcer even when they involve committing atrocities. He generally acts friendlier when compared to his cohort Night Rogue, though he is just as sadistic, sinister and ruthless as his ally, if not more so, turning a child into the Ice Smash just to show off his Steam Blade's ability to create Smash. He is also incredibly manipulative, and willing to play both his allies and enemies alike to achieve his goals. He posed as Sento's friend and mentor to manipulate him without remorse and has no compunction with backstabbing and eliminating allies once they have stopped being useful to him.

Blood Stalk's cruel and sociopathic traits becomes much more highlighted as the series progresses, especially after he is revealed to be Evolt, the entity that annihilated life on Mars. He becomes much more wrathful as Vernage and Sento continue to impede his plans, choosing to keep Sento around rather than erase his personality after he possesses him just so he can make him watch as he harms his friends. Evolt also often allows his bloodlust and sadism to get the better of him, choosing to put off destroying Earth in order to have a "final battle" with the Riders and to screw with them some more.

Evolt shows an apparent disdain for technology and innovation, claiming to Sento that science causes society becoming complacent and ultimately leads to war, though this may just be him trying to screw with Sento, as Evolt is shown advancing technology for his own purposes many times throughout the series. Evolt also seems to have an interest in humanity, and is greatly amused by their capacity and willingness to commit atrocities on one another. Though at the same time, Evolt regards humanity as being inferior to him and is greatly annoyed whenever a human manages to reach a comparable power level to him. While looking down on humans, Evolt seems to regard his own kind the Blood Tribe and in particular himself as being supreme to all other forms of life. Evolt's ultimate goal is a perfect reflection of his mindset: he seeks to destroy everything else in existence and leave only himself as the sole inhabitant of the universe. Despite Evolt's destructive goals, he can be reasoned with on some level and is willing to put aside his hatred and team up with his enemies should a greater threat present itself, such as his hedonistic older brother Killbus.

Trivia

 * Initially, the true identity of Blood Stalk was hinted to be Takumi Katsuragi before it was revealed to be Soichi Isurugi, and later Evolt.
 * Kamen Rider Evol is the second snake/cobra-themed Kamen Rider since Kamen Rider Ouja. Curiously, both are villainous Riders and share similar personalities.
 * Stalk provides the recap for episodes 22 and 37, and also participates in the recap for episode 9.
 * Evolt has many similarities with traditional depictions of the Devil, being a manipulator who makes deals offering power to others only to eventually betray them. Adding onto this, he has a snake-theme as Blood Stalk and Kamen Rider Evol Cobra, similar to how the Devil appears as a serpent in the story of Adam and Eve.
 * Whether his name is spelled as "Evolt" or "Evolto" is debatable, as a report in an episode has his name written as "Evolto", while supplementary materials for the move Be The One refer to him as "Evolt".
 * Having 7 forms in all (including Blood Stalk, all phases in Kamen Rider Evol, and his true form), Evolt has most of the transformations among the villains in Heisei Era of Kamen Rider.
 * In the entire Kamen Rider franchise including Showa continuity, the number of Blood Stalk's forms is the second best, only behind the Great Leader of Shocker, who has at least 8 confirmed incarnations and forms in total, if Grand Lord Crisis and Kamen Rider Decade are both included. However, if one includes his ultimate form as a separate form from his true form then Evolt is tied with the Great Leader for most transformations in the whole of the Kamen Rider franchise.
 * Evolt has a habit of saying "Ciao!" as his farewell phrase, though he is not the first villain to do this.
 * Since Evolt's older brother Killbus is stated to be the King of the Blood Tribe, this could mean Evolt is a prince. Evolt's official rank in the Blood Tribe is unknown though he seemed to be superior to Kamen Rider Blood and his two lackeys, suggesting Evolt may hold some sort of high position within his race.
 * As of the events of Kamen Rider Build NEW WORLD: Kamen Rider Cross-Z, Evolt is the only known survivor (albeit a revived one) of the Blood Tribe.
 * Evolt is the only main Kamen Rider villain to not only survive his respective series without turning good, but also achieve his main goals, obtaining his Feverflow transformation at the end of NEW WORLD: Cross-Z before leaving Earth. Though Evolt does acknowledge that there will still be time before he is able to assume his ultimate form.