Gamedeus

Gamedeus appeared in 2017 TV series called Kamen Rider Ex-Aid. Gamedeus (ゲムデウス Gemudeusu) was the thirteenth and final boss Bugster of Kamen Rider Chronicle. As per the rules of the game, the Ride-Player who has defeated and claimed the Gashatrophies of the thirteen Bugster bosses will be able to challenge Gamedeus as the final boss of the game.

While acting as navigator for a group of human Ride-Players, Poppy revealed the existence of the game's final boss, describing it as the final challenge to be faced by the Ride-Player who manages to defeat the twelve familiar Bugsters and claim their Gashatrophies.

Entrusted to beat Kamen Rider Chronicle by Emu, Nico Saiba realized that she would have to defeat Parado before facing the final boss, encouraging Taiga Hanaya to accompany her in confronting him.

According to Kuroto Dan, Gamedeus is the ultimate Bugster, transcending the power of any and all games. The only way to defeat Gamedeus is to obtain the power of Kamen Rider Cronus.

As theorized by Parado, since Cronus is the only one who can stop Gamedeus, Gamedeus would also have the power to stop Cronus as well, though Kuroto himself had assumed that Cronus could not be defeated via conventional means. With that in mind, Parado and Graphite went into the game world of Kamen Rider Chronicle to collect Gamedeus' virus data from the silver-colored Bugster Union form of Gamedeus. In an attempt to replicate the virus data, Graphite injected the virus into himself, but the power proved too much for him to handle. As Parado and Graphite faced Cronus yet again, Graphite transmitted the virus into Cronus' Buggle Driver II, which rendered the Pause ability useless. However, Laser Turbo made his appearance and neutralized the virus within the driver.

Graphite grew visibly ill as the Gamedeus virus multiplied within his body. He accepted his pain, however, as the price it would take to defeat Cronus and take back Kamen Rider Chronicle. Indeed, Graphite was able to use the Gamedeus virus to successfully block Cronus' ability to pause in their next engagement, however, Cronus retained the advantage by seizing control of all Energy Items.

When Cronus' Reset erased Hyper Muteki, Graphite, whose condition did not comprove due to time rewinding, was left as the only obstacle to him. Seeking to prevent the advent of Gamedeus, Cronus initiated Pause before Graphite could finished in battle only for Graphite to turn on Cronus in defense of the Kamen Riders, branding Cronus' move a dishonorable interruption. The resulting Restart led to Graphite being finished by Ride-Player Nico, granting her the last remaining Gashatrophy, Drago Knight Hunter Z. Seeing the assembly of Gashatrophies bringing forth Gamedeus, Cronus attempted to initiate Reset only to be thwarted by the new Energy Item Save developed by Kuroto Dan. With that, Gamedeus finally made his appearance.

Once released, Gamedeus, acting on Masamune's changes to his behavior programming, proceeded to unleash his disease all over the population. Fortunately, Laser Turbo and Genm were able to create a vaccine for Gamedeus's virus, which was successful, only for Cronus to barge in, destroy Gamedeus' physical body and uses his Gashacon Bugvisor II to suck up the data and inject his data right into his systems. It results with Masamune completely assimilating Gamedeus, becoming a Bugster. But the sacrifice by Poppy to fortify the Doctor Mighty XX Gashat's anti-virus which Parado uses to force Gamedeus out of Masamune's body, grabbing the monster so the antivirus can destroy them both and end the Bugster threat for good.

Around the time that Gamedeus appeared, Masamune's former business partner Johnny Maxima stole the Gashacon Bugvisor of Graphite. As the Bugvisor contained fragments of Gamedeus' data, Johnny uses it to become a stronger form of Gamedeus.

In an event witnessed by Sento Kiryu, Gamedeus was among numerous monsters whom engaged the first 18 Heisei Riders before being wiped out by the Vortex Time Break of Kamen Rider Zi-O BuildArmor.

Normal

 * Godlike Powers: As the final boss of Kamen Rider Chronicle, Gamedeus possess the greatest power of all Bugsters.
 * Worldwide Pandemic: Like the Pac-Man Virus, Gamedeus's virus can affect multiple people at the same time, even Bugsters.
 * Pause Immunity: It can be assumed that Gamedeus himself is immune to Cronus' Pause ability, similar to Hyper Muteki.
 * Bugsters Power Channeling: He can briefly manifest an image of a Bugster's head on his chest, and then use a technique unique to that Bugster:
 * Swordmanship: By channeling to Kaiden Bugster's power, he can skillfully slash his opponents.
 * Magic Attacks: By channeling to Aranbura Bugster's power, he can unleash a powerful ice attack upon his opponents. It is the enhanced version of Aranbura's The Legendary Magic (伝説の魔法 Densetsu no Mahō).
 * Transcendent Secret Technique: Explosive Crimson Dragon Sword (超絶奥義：紅蓮爆竜剣 Chō-zetsu Ōgi Guren Bakuryū Ken): By channeling to Guren Graphite's power, he can perform a stronger version of Guren Graphite's signature move.

Weaknesses

 * Kamen Rider Cronus: As the symbol that was designated to go against Gamedeus. Cronus is one of the few riders who logically can defeat Gamedeus.
 * Pause: The key ability exclusively for Cronus to defeat Gamedeus. It can stop the flow of time around Cronus. It is also used to prevent any defeated Bugsters from being revived.
 * Doctor Mighty XX Gashat: This Gashat is specifically designed to neutralize Gamedeus's powers, as it acts like a vaccine against Gamedeus virus. It didn't only cure all infected patients of the virus, but also weakened Gamedeus significantly.

Super

 * Regeneration: The cultivation of Bugster Virus in its body is accelerated to the point that damaged parts are quickly regenerated.
 * Bugster Summoning: Super Gamedeus is able to summon any of Kamen Rider Chronicle's component Bugsters.
 * Game Area: Super Gamedeus can generate a massive Game Area the size of a town. Because the inside of the Game Area is filled with Gamedeus' Bugster Virus, those within it are at an increased risk of being infected. In addition, the Game Disease of those infected will progress at an increased rate.

Arsenals

 * Deus Fabunil: Super Gamedeus' telescopic arms, from which it is able to shoot energy projectiles.
 * DeuSlasher: A gigantic version of the DeuSlasher forms part of Super Gamedeus' lower body, which it can still use to attack enemies.