Kamen Rider Decade

"I'm just a passing-through Kamen Rider! Remember that!"

- Tsukasa

Though the protagonist of Kamen Rider Decade, Tsukasa Kadoya is treated as a villain due to Narutaki prophecy of the Rider War that he causes and is also the Decade incarnation of the Great Leader of Shocker.

History
Originally, Tsukasa was the leader of Dai-Shocker who lost his memories and edded up in another world where he was found by Natsumi Hikari and works for her grandfather as a photographer. However, when Natsumi is sucked into pocket dimension where finds the Decadriver, Tsukasa learns from a youth named Wataru Kurenai that this world will end, and that he is needed to protect it. After finding Natsumi, Tsukasa becomes Kamen Rider Decade to battle the various monster while confused by both his actions and the cards' powers' fading. When time suddenly freezes, Wataru appears, revealing the status of the worlds and assigning Tsukasa the task of traveling into the other worlds to stop the dimensional chaos inflicted on his own world by meeting the nine Riders of each of the other dimensions. Along joined by the World of Kuuga's Yuusuke Onodera, Kamen Rider Kuuga, Tsukasa traveled to Worlds of Kuuga, Kiva, Ryuki. While visiting the Worlds of Blade and Faiz, Tsukasa encounters Daiki Kaito, Kamen Rider DiEnd as he ventured to the World of Agito.

Upon arriving in the World of Den-O, Tsukasa becomes involve in the adventures of Kamen Rider Den-O as he helps them fight the Oni Rider Brothers before returning to the present time to continue his journey to the Worlds of Kabuto and Hibiki. With the journey appearing to be over, Tsukasa returns to what appears to be Natsumi's world, only to learn it is an alternate universe called the World of the Dark Riders. There, refusing to live in such a world, Tsukasa gains the K-Touch that enables him to become Complete Form to take out most the Dark Riders. Knowing that their journey is not really over, Tsukasa and the Hikari Studio group venture to the Worlds of DiEnd and Shinkenger, confronting the Ayakashi Chinomanako who threatens the latter world's balance when he obtained DiEnd's powers.

While visiting the Worlds of Black RX, Black, and Amazon, Tsukasa confronts Apollo Geist of Dai-Shocker. Soon after, Tsukada arrives to the World of Decade, his home world. There, tricked by Nobuhiko Tsukikage to beat the other Kamen Riders in a tournament, Tsukasa regains his memories as the leader of Dai-Shocker and resumes his place in the organization. However, Tsukasa finds himself overthrown by Shadow Moon and a revenge-driven Sayo as Priestess Bishium through Rising Ultimate Kuuga. After meeting Joji Yuki a former Dai-Shocker scientist, Tsukasa resolves to stop Dai-Shocker and leads all the Kamen Riders to defeat them while makig peace with Sayo.

However, arriving the World of the Rider War, Tsukasa learns that the worlds he saved are still merging and ceasing to be because of his actions while facing the Fangirezed Super Apollo Geist. Once Apollo Giest is destroyed, Tsukasa learns we was supposed to destroy the Kamen Riders of the alternate worlds with the nine original version Kamen Riders gathering to force Decade on the path he is suppose to take. Accepting his fate, Decade destroys many Riders and turns them into cards. He is assisted by Yuriko Misaki, Electro-Wave Human Tackle. However, when finding himself facing Natsumi as Kamen Rider Kivala, Decade allowed himself to be destroyed as his actions and death are the catalyst to restore the worlds at the cost of his existence. However, Natsumi finds a way to revive him through the use of a picture and the A.R. Riders' memories. From there, Decade leads the A.R. Kamen Riders against Super Shocker before he and Kamen Rider Double team up to destory Ultimate-D. With his mission over, Tsukasa resolves to travel the worlds.

Let's Go Kamen Riders
A mishap caused by the Greeed Ankh unintentionally altered the timeline which enabled Shocker to utilize the Core Medal to create the Shocker Greeed which defeated the Double Riders and seemingly erased the legacy of the Kamen Riders from history. In 2011, after Kamen Rider New Den-O's attempt to repair the damage, he along with Kamen Rider OOO and M-Ankh awaited execution. However, it was revealed the Double Riders had their brainwashing removed by a Shocker scientist.

The Double Riders joined with New Den-O and OOO to fight Shocker's forces, but were eventually defeated. When the order was given to kill everyone, V3 suddenly appeared, asserting that there were more than four riders. V3 was soon followed by all the other revived riders that came after him, as even though Rider history was changed, the people's memories haven't changed. Decade appeared after the three 90s riders and the first eight Heisei riders, defeating the Paradoxa Undead, Tiger Orphnoch and Shadow Moon in quick succession.

After the riders were united, they faced off against Shocker's Great Leader. Later, when joined by a force of extra riders, Decade got into his Machine Decader, and alongside all the other riders in their vehicles performed the "All Rider Break", ramming into the Rock Great Leader and defeating it once and for all.

Kamen Rider × Super Sentai: Super Hero Taisen
Tsukasa appeared in a movie alongside the Gokaigers in a Super Sentai meets Kamen Rider event, Kamen Rider × Super Sentai: Super Hero Taisen.

Doktor G resurrected and gathered all defeated Rider villains, recreating Dai-Shocker. He told Tsukasa that the Riders and monsters needed to destroy the Super Sentai to ensure the survival of the Riders, and, answering that, Tsukasa took control of the new Dai-Shocker, becoming its Great Leader again to battle the Super Sentai and also the Dai-Zangyack, a new union of Super Sentai villains led by the Gokaiger's Captain Marvelous. As the Great Leader of Dai-Shocker, Tsukasa apparently destroyed many Super Sentai teams, apparently leaving only GokaiRed and GokaiGreen alive, while Decade himself was seemingly the last remaining Rider. After he was wounded in his battle against GokaiRed, Doktor G used the opportunity to overthrow him and take control of the organization. The story about Riders needing to destroy Sentai to survive was a lie, and Doktor G was actually allied with Dai-Zangyack and using both GokaiRed and Decade to destroy the other heroes and afterwards kill the nominal leaders of the two organizations.

However, Tsukasa and Marvelous already realized that trap from the beginning before the war starts. The destruction of the Super Sentai actually just an act and the truth was, all the Super Sentai and Riders were just sent into a rift between dimensions. Tsukasa turned against Dai-Shocker and Dai-Zangyack, supported by all other Riders and Super Sentai. Alongside the Gokaiger, he killed General Shadow. In the end, he faced Doktor G, the man behind the new Dai-Shocker, and defeated him with the help of the Super Sentai team Goseiger, and Kamen Riders Ryuki and Blade. However, after being defeated, Doktor G was revealed to be Decade's old enemy, Narutaki, who escaped afterwards, and his real identity was left a mystery.

Super Hero Taisen Z
Space Sheriff Gavan Type G, alongside Kamen Rider Beast and Yellow Buster invaded the fortress of the Space Crime Syndicate Madou on Earth. However, inside, they're overrun by the forces of Space Shocker, which had allied itself with Madou. Gavan was separated from the others and trapped by Shocker's forces, when Kamen Rider Fourze arrived, answering the call for help of GokaiSilver, who asked for reinforcements to help in the attack. Fourze brought with him more allies, including Meteor, Super-1, the Super Sentai teams Choushinsei Flashman, Tokusou Sentai Dekaranger and Decade himself to confront Space Shocker. Decade briefly fights against Tortoise Undead and afterwards pierces through a Pteranodon Yummy.

Afterwards, Decade presumably stays fighting against the other reinforcements brought by Space Ikadevil, while Fourze is thrown out of the area. Space Ikadevil himself is finished by the Super Sentai team Gokaiger, while Gavan and Meteor leave to fight against Space Shocker's and Madou's leaders. After the battle is over, Decade appears on top of a nearby cliff alongside the other heroes who appeared to help to say goodbye to Gavan and the others.

World of Monsters
Decade was summoned along with OOO by the alternate version of Haruto, taking the children to the shop. Before taking the children away, he thinks that he has arrived in the World of Wizard, but Haruto tells him that he is mistaken. He is summoned again by Amadum to retrive back the Fourze Rider Ring from Haruto. He then teamed up with Haruto along with the Heisei Riders to fight Amadum and his monsters. However, Amadum was too powerful for the Riders as he takes their items from them, until Gaim arrives. Gaim easily beats Amadum up as the Riders regaining their items to transform into their final forms. After Amadum is defeated, and the Rider Rings gone, Tsukasa leaves to continue his journey, stating that Haruto and him will meet again

Kamen Rider Taisen
Tsukasa returns in Kamen Rider Taisen. He is informed by Shotaro that both Heisei and Showa Riders are starting a war. However, both are confronted and attacked by Black and Black RX, who saw the Heisei Riders as unforgivable nuisances. Shotaro asked Tsukasa to find the rookie Heisei Rider of Zawame, Kota Kazuraba who was confronted by Takeshi Hongo ,who had Mitsuzane killed and turned into a Legendary Lockseed, at Drupers. Once finding Kota at Drupers, he helps Kota with leading the Heisei side. He, Haruto, Kota, Takumi , and Keisuke soon realized that almost all Riders have been brainwashed by Ren Aoi/Kamen Rider Fifteen into fighting one another, which is also how Hongo became so ruthless, and eventually calls a truce to stop the war and restore the Riders' alliance together

Kamen Rider: Battride War
"Quick, Canaria is hoping on us!"

- Decade telling Wizard to quickly destroy the Mnemozyne.

Kamen Rider Decade appears as a Main Rider in the video game Kamen Rider: Battride War, which unites the riders of the Heisei era from Kuuga to Wizard.

In the game, Decade is the only character to picked 3 from 9 main pre-Decade's Heisei Kamen Ride Forms (mostly their main forms), in which Decade able to access his normal sword attacks with the other Kamen Rider's ground special attacks. While performing a finishing moves (Final Attack Ride) in some Kamen Ride Forms, it will revert back to Decade. His ultimate form, Complete Form can access an ultimate attacks anytime depends on the some Kamen Ride to be used on. Like Blade, Beast and Wizard Infinity Style, Decade can perform a normal aerial slash twice.

Rider Powers
He mostly appeared as Kamen Rider Decade. Only in Episode 14 of Kamen Rider Decade.

Decade can transform into any previous Kamen Rider with access to that respective Rider's powers and weapons. However, during the battle against Kamen Rider Dark Kiva in the Nega World, Tsukasa has lost his power to transform into Kamen Rider Decade as well as all cards are turning into black. Later, Tsukasa was able to restore his power and all cards are return to normal. One of Tsukasa's particular gestures is dusting his hands, or running a hand along the blade of his sword, while fighting.
 * Height: 192cm
 * Weight: 83kg
 * Punching Power: 4t
 * Kicking Power: 8t
 * Maximum Jump Height: 25m
 * Maximum Running Speed: 100m/6

Complete

 * Height: 199cm
 * Weight: 102kg
 * Punching Power: 12t
 * Kicking Power: 16t
 * Maximum Jump Height: 50m
 * Maximum Running Speed: 100m/4

Complete Form is the true form of Decade that is able to manipulate the power of other Riders' final forms, accessed through the K-Touch once he regains the powers of all of the Heisei Kamen Riders. Referred to as the "King of the Rider Worlds", he wears the Decade Complete Kamen Ride Card on his helmet, embedded in the Decade Crown, and the others' Kamen Ride Cards on his chest. When Complete Form features the most powerful forms of the Heisei Kamen Riders on the cards (as seen in the Super Adventure DVD, Movie War 2010, and Kamen Rider Wizard Episode 53), this version of Complete Form is called Strongest Complete Form. In the novel, Natsumi creates a Kamen Ride card which Tsukasa as Kamen Rider Decade Cyan Version uses it which summons all 9 Heisei Riders to perform their finisher attacks at Narutaki before they could turn themselves into Rider Cards and attached to Decade into becoming Final Kamen Ride Tsukasa which is a cyan version of Decade Complete Form only without the K-Touch.

Appearances: Episode 21 Ryuki Survive,Faiz Blaster, (Kabuto Hyper), 22 (Kiva Emperor), 23 (Hibiki Armed), 24 (Den-O Liner), 25 (Blade King), 26 (Kabuto Hyper), 27 (Agito Shining), All Riders vs. Dai-Shocker (Jumbo Formation), World of Televikun (Strongest Complete Form), 29 (Faiz Blaster), 30 (Ryuki Survive), 31 (Diend) Movie War 2010 (Strongest Complete Form), Kamen Rider Wizard episode 53 (Strongest Complete Form)

Final Form Ride
In Kamen Rider Decade: All Riders vs. Dai-Shocker, [[Kamen Rider Diend uses a Final Form Ride card that turns Decade into the Jumbo Decadriver, a larger version of the Decadriver which is worn by a Diend Kamen Ride Card-summoned Kamen Rider J to transform into Decade Complete Form Jumbo Formation'''. This complete form is identical in appearance to the regular, except he is J's Jumbo size, and does not wear the K-touch but the Decadriver on his belt buckle.

Violent Emotion
For most of the first act of Kamen Rider × Kamen Rider Double & Decade: Movie War 2010, Decade assumes his dark rider form called Kamen Rider Decade Violent Emotion. This form is Decade's false final transformation into the destroyer of worlds, with Decade's body in a lighter shade of magenta, the eyes assuming a more sinister appearance, and the normally yellow Signal Pointer (the light on Decade's helmet) is violet. While this form appears similar to Decade's normal form, it is drastically stronger, both possessing greater combat capability (enough to go toe-to-toe with Kuuga Ultimate Form and destroy countless other riders) and able to use Attack Ride cards such as Clock Up without having to transform into the associated Rider first.
 * Height: 192 cm.
 * Weight: 83 kg.
 * Punching Power: 5 tons
 * Kicking Power: 10 tons
 * Maximum Jump Height: 30 meters
 * Maximum Running Speed: 100 meters per 5 seconds

Decadriver

 * Change announcement: KAMEN RIDERR
 * Form Change announcement: FORM RIDER
 * Attack announcement: ATTACK RIDER
 * Rider Form change announcement: FINAL FORM RIDER 
 * Final attack announcement: FINAL ATTACK RIDER
 * Decade Complete announcement: FINAL KAMEN RIDER

Tsukasa transforms into Decade through the use of the Decadriver belt that is based around the Rider Cards. By inserting a card into the Decadriver, Decade can invoke the cards' abilities. In Complete Form, the Decadriver is moved to the right side of his belt where Decade inserts his Final Attack Ride Cards and activates them by touching the Decadriver's window.

Ride Booker
Decade's primary weapon is the Ride Booker which has three modes: the default Book Mode, which is placed on the left side of his belt and holds the Rider Cards that Decade uses in his arsenal, Gun Mode which can be used to execute the Dimension Blast finisher and Sword Mode which can be used to execute the Dimension Slash finisher.

When fighting Gyūki, Decade briefly fought as Ryuki with a red bullfighting cape adorning the blade of Sword Mode. In either Mode, Decade primarily uses the Ride Booker in the place of the Heisei Kamen Riders' signature weapons, regardless if in the form of blades or firearms, unless it is weapons with a nature like that of Kuuga's, Agito's, or Kiva's.