Zamasu

"Evil is violence like that of the Babarians and conceit like that of Son Goku, who would trade blows with the gods. Humans use their god-given wisdom for evil and spoil our beautiful world. The humans who have gained wisdom are true evil. Does this not strike you as half-hearted? What good are gods if they do not destroy evil?!"

- Zamasu to Gowasu. "Again? Once again, Mortals? Mortals constantly imitate Gods. Why is that? It's because Gods are great and beautiful. But is it woeful? Is it to be pitied? What is good when done by Gods becomes evil when done by Mortals and, ultimately, becomes sin!"

- Zamasu during his final battle. "My form is justice. My form is the world! Revere me. Praise me. The noble and beautiful, immortal and most powerful god, Zamasu!"

- Fusion Zamasu

Zamasu (in Japanese: ザマス), alternatively spelt as Zamas in the manga, is the main antagonist in the "Future" Trunks Arc of Dragon Ball Super. There are two different timeline versions of him working together to kill all of the mortals in the multiverse - Goku Black and Future Zamasu.

Zamasu was formerly the North Kaio of Universe 10 and the apprentice of Gowasu, the Kaioshin of Universe 10. He holds an incredibly black and white viewpoint, believing that the gods are all good, whereas mortals are evil and need to be wiped out for the good of the multiverse.

He was voiced by Shin-ichiro Miki who also voiced Mizuki.

Personality
While a man who cares for the development and prosperity of the universe, the present Zamasu often questioned the worth of humanity, not trusting in their ability to handle conflict, as they were prone to commence war in a repeated cycle. He also did not agree with how the Kais would not be more directly involved in mortals' actions, like the Gods of Destruction. Despite this, he acknowledged his lack of personal experience and was willing to diligently listen to his teacher Gowasu's words. To which, he was a humble, ordinary, deferential, and level-headed man with just goals, as Gowasu noted by how well-balanced he would brew tea, implying that he was a just and honorable man. In battle, he is shown to be a very calm, regular, and methodical fighter, carefully perceiving his opponent's attack style and seamlessly countering in a fluid manner.

However, after meeting Goku, his views radically changed, and his distrustful and depreciatory nature towards humanity only grew. Annoyed at Goku's carefree attitude and lack of respect, his distaste for the gods not quelling the dangerous nature of mortals evolved to a radicalism-level. Shocked at how a mortal like Goku could gain a power rivaling gods (or even obtain such power to begin with) and so recklessly challenge one, Zamasu came to sternly believe that humanity by nature is an evil.

However, the future version of Zamasu has truly fallen into the depths of evil, speaking of humans and of the Saiyans as "mere humans" who are inferior to him. Similar to his partner, Goku Black, he has a sadistic, merciless, and unpleasant goal of ridding the entire universe of humans in the name of "justice", believing them to be the source of all evil, and he refers to a world without them as a "utopia". Future Zamasu also seems to have a deep hatred for Goku, as he considers killing him as his main goal and something only he should do (a trait his past counterpart is slowly developing). While battling Goku and Future Trunks, he constantly speaks about how humans misuse their "god-given wisdom" for their own personal gain. Also, Future Zamasu refers to his immortal body as befitting for him.

Main Timeline
Goku first encounters Zamasu chronologically when he, Beerus and Whis go to see him and his master, Gowasu. Goku spars with Zamasu and defeats him. He offers his hand to Zamasu, but the latter refuses. Zamasu's defeat at Goku's hands would only further his hatred of mortals.

Zamasu later suggests to Gowasu that they wipe out the primitive and violent humans on Planet Babari. Gowasu, however, states that only Gods of Destruction can carry out that act. Gowasu then uses the Time Ring to allow him and Zamasu to travel to the future of Babari. He also gives Zamasu an earring that makes him a Kaioshin, as apprentices cannot go.

The two fist bump and say "1000 years", transporting them to the future of Babari, where the planet's natives are fighting each other. This only serves to further Zamasu's belief that mortals are all bad. A Babari attacks the two, but Zamasu slices it in half, against Gowasu's wishes.

Returning to the future, Zamasu returns the earring Gowasu loaned him and debates his master on whether they can learn from mortals.

The Future Zamasu later appears in Future Trunks's timeline, wearing a green earring instead of a pair of orange ones, giving him the rank of Supreme Kai. Zamasu stopped Goku Black from using his Kamehameha, reminding Black of his promise to allow him to kill Goku. He then engages Goku in combat along with Goku Black. Future Trunks aids Goku in his fight, Goku fought Black and Trunks fought Zamasu. Goku is overpowered by Goku Black and Trunks manages to stab Zamasu but his wound healed (due to having an immortal body). He then holds down both Goku and Trunks so that Black's Kamehameha blast can hit them. With Goku, Future Trunks, and Vegeta defeated by the duo, the Resistance saves them and then the three of them flee to the past. Goku Black is angered but Zamasu then says that they will return.

Back in the present timeline, Present day Zamasu gets Gowasu some tea. Gowasu is watching the fight between Goku and Hit on GodTube. Zamasu sees the Super Dragon Balls on the monitor and asks Gowasu what they are. When he got his answer he became interested in the wish orbs. He then arrives in Zuno's place in Universe 7 and asks him about the Super Dragon Ball's and Son Goku.

Zamasu later tries to kill Gowasu and steal his time ring, but his attempt is foiled by the arrival of Goku, Beerus, Whis and the Universe 7 Kaioshin. Whis then reveals Zamasu's true plan to Gowasu. Zamasu then attempts to attack Goku, but his attack is blocked by Beerus, who disintegrates him.

However, this does not put an end to Future Zamasu, who is still working with Black in the future. When Goku, Trunks, Vegeta and Bulma traveled to the future, he and Black detected the former three's ki and went to confront them. There, Black revealed his origins to the Saiyans and two battle them, forcing Goku Vegeta and Bulma to retreat while Trunks holds the two Kaioshin off.

Goku and his friends later return, having learned the Mafuba technique to contain Zamasu. However, Goku Black distracts Goku and Vegeta with his newfound power, forcing Trunks to learn the technique in just a few minutes. To buy time for Trunks to practice the technique, Bulma attempts to distract Zamasu by seducing him. However, Zamasu is not amused, and quickly casts Bulma aside.

Before Zamasu can kill Bulma, Trunks and Mai arrive, and Trunks uses the Mafuba to seal Zamasu in a pot. However, the three then realize Bulma forgot the seal to place on the pot, allowing Zamasu to break free. Sensing something wrong with Zamasu's energy, Goku Black goes to see what's going wrong. After Zamasu tells him that they underestimated the true power of humans, the two fuse into Fusion Zamasu, with Zamasu proclaiming himself to be the most powerful god.

Fusion Zamasu summons a halo and begins launching energy blasts randomly. In order to defeat Goku and Vegeta, Zamasu creates a large energy sphere and launches it at the two Saiyans. However, Goku launches it back at him, resulting in half his face becoming horribly disfigured. As the battle goes on, Fusion Zamasu's body starts to become horribly unstable as a result of both Goku Black's mortality and Zamasu's immortality contradicting each other, as well as Zamasu's undying hatred for mortals and the contradictions of the gods.

In order to defeat Fusion Zamasu, Goku and Vegeta fuse into Vegito. Initially, they fight Fusion Zamasu evenly, though Zamasu appears to gain the upper hand when he knocks Vegito onto the ground and charges at him with an energy blade. However, Vegito summons an energy blade of his own and impales Zamasu through his chest, informing him that he's not immortal because his body is fused with Son Goku's. Zamasu responds by telling him that he has repurposed Goku's and the god's sins for a greater purpose.

Zamasu then frees himself and inflates his body to give him more power. Though Vegito appears to gain the upper hand, the time limit on the Potara earrings Goku and Vegeta used wears off early because of the energy Vegito used, resulting in them unfusing. However, Future Trunks arrives wielding his sword, which now having an energy blade, and fights Zamasu. Eventually, using the energy gathered from the people of Earth to charge up his sword. Goku and Vegeta also give Future Trunks their energy, to provide him with the boost he needs defeat Fusion Zamasu. Trunks then stabs Fusion Zamasu with his massive energy sword and cuts him in half, resulting in the end of both Goku Black and Zamasu.

Or so they thought. Fusion Zamasu took the opportunity to shed his body. Zamasu's essence then enveloped the Earth and began assimilating the entire universe. Goku, Trunks and Vegeta attempted to stop Zamasu using a Kamehameha, Galick Gun and Final Flash respectively, but to no avail. Zamasu's faces in the sky then began firing lasers at the Earth, killing all life on the planet save for the heroes, who were protected by a dome created by the Kais.

However, while searching for a Senzu bean, Goku came across the button Zen'O had given him to summon him at any time. Goku then used the button to summon the Zen'O of Future Trunks's universe. Goku directed Zen'O to Zamasu, who had rapidly overtaken the multiverse and even began to affect Goku's timeline. Zen'O then used his power to destroy the entire multiverse, wiping out Zamasu once and for all.

Goku, Vegeta, Future Trunks, Bulma and Future Mai then returned to Goku's timeline. In order to be with their friends again, Trunks and Mai traveled to a timeline where Zamasu and Goku Black had not yet attacked to warn the Beerus of that timeline about Zamasu.

Alternate Timeline
An alternate Zamasu managed to kill Gowasu and steal a Time Ring, allowing him go to an alternate future, kill the Gowasu there and team up with his alternate counterpart. Prior to this, Zamasu used the Time Ring to travel to when the Super Dragon Balls were usable, and wish to switch bodies with Goku. This Zamasu would later come to be known as Goku Black.

Goku Black then traveled to Future Zamasu's timeline, killed the Gowasu there, and teamed up with Future Zamasu. They then used the Time Rings to travel to when the Super Dragon Balls were usable and used them to give Future Zamasu an immortal body. With their newfound power, the duo exterminated all of the Gods in Future Trunks's timeline and destroyed the Super Dragon Balls so they could never be used to undo their actions.

Powers and Abilities
Zamasu is a fighting prodigy. According to Goku, Zamasu's power far surpasses the power of Universe 7's Kaioshin and happens to be superior to the former Kaioshins who were killed/absorbed by Majin Buu, though he is not as strong as Super Saiyan 2 Goku post-training with Whis.

His future counterpart can fight on par with Super Saiyan Blue Goku when he is at full power, as well as stand his ground against Super Saiyan 2 Future Trunks. Zamasu also share a similar ki signature with his partner in crime, Goku Black, although Black happens to be superior in strength.

Fusion Zamasu's power is infinitely higher than that of Goku, Vegeta, and Future Trunks' full power combined. His power is stated to have no end by Gowasu, meaning that if Zeno-Sama had not destroyed him, he would have grown in power indefinitely until he surpassed all the Gods and Angels. He can break all the bones in Goku and Vegeta's arms just by catching their fists and crushing them slightly, and he effortlessly breaks Future Trunks' sword in two. It took Goku's most powerful Kamehameha ever (resulting in his arms being broken) to actually cause some damage to his face, after which an angry Zamasu simply broke his leg with another crush of his hand. Goku using Kaioken was able to knock him to the Earth and shatter his Halo, although he broke his other leg as a result, after which Zamasu grew enraged and increased his power far beyond what he had been using before.

Mutated Fusion Zamasu is powerful enough to fight equally with Super Saiyan Blue Vegito, who fights him all-out. He eventually increases his size and while it comes at the cost of his speed, it buffs his power even higher than before.

Fusion Zamasu's non-corporeal form is so powerful that he can absorb the entire Universe and possibly all other Universes beyond, and even begin to break into the Present Timeline, however even he is no match for Zeno-Sama, who uses his ultimate attack to wipe him out for good.

God Split Cutter
One of Zamasu's most notable attacks. Zamasu creates a field of purple energy around his right hand, creating a powerful Ki Blade that can be fired or used to block attacks.

Instantaneous Movement
Like the other Kais, Zamasu can travel anywhere he desires. Including other universes.

Barrier of Light
Zamasu combines both two sources of his power and a halo of light appears behind his back.

Wall of Light
Fusion Zamasu creates a huge purple entity from pure Ki, resembling a monstrous bird. Despite its ethereal nature, the entity appears to be its own being, as it roars occasionally. It can both attack and protect. Anything that touches it will be eliminated; knocked out.

Lightning of Absolution
Fusion Zamasu fires purple bolts of lightning from either his Ring or Wall of Light.

Blades of Judgement
From his Barrier of Light on his back, Fusion Zamasu fires a barrage of red energy blades that can strike the opponent. If any of the blades hit the ground, they will burst in a destructive explosion.

Holy Wrath
Fusion Zamasu's ultimate attack; It is Zamasu creating a small sun-like energy sphere in his hand and then throws it at his opponent, expanding it into a huge energy ball. It is used in a similar fashion as Broly's Omega Blaster.

Trivia

 * Zamasu is very similar to the Christian Devil: as he is formerly a servant of a god who became evil because of his desires considered wrong by his master.
 * Zamasu shares many similarities with Demon God Demigra from Dragon Ball Xenoverse. Both have pointed ears, wear green earrings, are prideful and adament in their divine superiorty over mortals and other gods, attempt to wipe out the Multiverse, and serve as foes to Future Trunks among other DB heroes.
 * Zamasu is also very similar to Zeref Dragneel since both are immortal and both question the acts of humanity.
 * Zamasu is the first and only Kai to turn evil.
 * Zamasu's main way of fighting is using an Energy Blade.
 * Future Zamasu and Goku Black have the highest body count in the series. Being responsible for the deaths of Goku, Goten, Chi-Chi, Present and Future Gowasu, Future Bulma, all the gods in the multiverse, and nearly every mortal in the multiverse.