Genocider

Beast Emperor Genocider is a chimeric Mirror Monster made up of Evildiver, Metalgelas, and Venosnaker.

Obtained through the Unite Vent Advent Card after Ouja used two spare Contract Cards to Contract the stray Monsters of defeated Riders, Genocider is a combination of Kamen Rider Raia's Evildiver, Kamen Rider Gai's Metalgelas, and Kamen Rider Ouja's Venosnaker. As such, it is an amalgamation of all three: the body of Metalgelas, Venosnaker attached onto its back as a long neck and tail, Metalgelas' face and horn on Venosnaker's head, and Evildiver strapped to the back of the creature, the front edges of its wings sprung up to form an 'X' shape.

Genocider first appeared after Asakura contracted Evildiver and Metalgelas as well as his original contract monster, Venosnaker. On many occasions, Asakura would summon Genocider merely to intimidate the other Riders, it rarely actually entering battle. When it did, however, it commonly ran at the opponent and shot venom at them. Genocider played a role in the death of Goro, who replaced Shuichi Kitaoka as Kamen Rider Zolda, and the destruction of Magnugiga. It's unknown what happened to Genocider after Asakura died in the series. However, the ending implies that he never existed afterwards.

In the alternate ending of Kamen Rider Ryuki, Asakura unites his monsters to form Genocider and aims to finish Femme off for good. He's interrupted by Ryuga, who summons Dragblacker to ram Genocider, foiling Asakura's plan. Ryuga then attempts to kill him with his own Final Vent, but Asakura was able to evade the attack and the attack hit Genocider instead, destroying all three Contract Beasts. This reverted Asakura as Ouja to Blank Form.

Trivia

 * TBA