|This article is about a/an Mirror Monster in Kamen Rider Ryuki.|
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.
Kamen Rider Ryuki
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.
Kamen Rider Ryuki: Episode Final
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.
- Dragreder (by accident)
Obtained through the Unite Vent Advent Card, Genocider appears as a combination of Kamen Rider Raia's Evildiver, Kamen Rider Gai's Metalgelas and Kamen Rider Ouja's Venosnaker. All three components of Genocider are contracted to Ouja and are used as either intimidation or to perform a Final Vent.
- Doomsday (ドゥームズデイ Dūmuzudei): A vortex opens up on Genocider's chest, with Ouja corkscrew-kicking his opponent into it.
In a S.I.C. Hero Saga story, Asakura had hijacked almost all of the contract monsters, using the Unite Vent and Survive cards to combine them into Genosurviver. It's unknown what its abilities are as it never appeared in the show. It only appeared in the first Ryuki S.I.C. Hero Saga story in Monthly Hobby Japan magazine, Masked Rider Ryuki: Advent Calendar (MASKED RIDER RYUKI -アドベントカレンダー- Kamen Raidā Ryūki: Adobento Karendā).
After Asakura stole Knight's Survive Card and and transformed into Survive mode, Venosnaker evolves into Venoviper. As Yui just happened to be nearby, Ouja summons Venoviper while holding Yui as its hostage. He then uses his new Unite Vent card with all the Advent cards he's gathered up until now from the Riders he defeated, with the Darkwing card which he also stole from Knight. All of his monsters, as well as Dragreder which just happened to be nearby, combine to form Genosurviver (ジェノサバイバー Jenosabaibā). However, since Dragreder still belongs to Ryuki, its head starts snapping at Venoviper's head. When Genosurviver starts to run out of control, it tries to attack and destroy Mirror World. Kitaoka shows up saying that he knew "something weird" was going on in Mirror World, since he was in his car when its windscreen just cracked. He transforms into Zolda, summons Magnugiga and performs the End of World, blowing everything away with the beast destroyed for good.
- This Mirror Monster's name is misspelled as Genosider on some versions of its Advent Card.
- Genocider's name comes from the word Genocide which means 'deliberate and systematic destruction, in whole or in part, of an ethnic, racial, religious, or national group', as it mainly focused on Genocider's Black Hole ability which can suck nearly everything.