Cerebeast

Cerebeast, also known as the Beast Emperor or Genocider, is a chimeric Mirror Monster made up of Evildiver, Metalgelas, & Venosnaker.

Appearance
Obtained through the Unite Vent Advent Card, Cerebeast appears as a combination of Kamen Rider Sting's Evildiver, Kamen Rider Thrust's Metalgelas, & Kamen Rider Strike's Venosnaker. All three components of Cerebeast are contracted to Strike & are used as either intimidation or to perform a Final Vent.

Cerebeast

 * Venosnaker
 * Evildiver
 * Metalgelas

Genosurvivor

 * Venoviper
 * Evildiver
 * Metalgelas
 * Dragreder (by accident)
 * Blackwing
 * Volcancer
 * Destwilder
 * Gigazelle
 * Biogreeza
 * Blancwing

Cerebeast
Obtained through the Unite Vent Advent Card, Cerebeast appears as a combination of Kamen Rider Sting's Evildiver, Kamen Rider Thrust's Metalgelas, & Kamen Rider Strike's Venosnaker. All three components of Cerebeast are contracted to Strike & are used as either intimidation or to perform a Final Vent.

Doomsday (Final Vent): A vortex opens up on Cerebeast's chest, with Strike corkscrew-kicking his opponent into it.

Genosurvivor
In the video game Kamen Rider Dragon Knight: Fight to Survive, Pryce had managed to contract almost all of the Advent Beasts, using the Unite Vent & Survive cards to combine them into (the tentatively named) Genosurviver. It is unknown what it's abilities are as it never appeared in the show.

After Pryce borrowed Wing Knight's Survive Card & transformed into Survive Mode, Venosnaker evolves into Venoviper. He then uses his new Unite Vent card with all the Advent cards he's gathered up until now from the Riders, with the Blackwing card which he also borrowed from Wing Knight. All of his monsters, as well as Dragreder which just happened to be nearby, combine to form Genosurviver. However, since Dragreder still belongs to Dragon Knight, its head starts snapping at Venoviper's head. When Genosurviver starts to run out of control, it tries to attack & destroy Ventara. Chance shows up saying that he knew "something weird" was going on in Ventara, since he was in his car when its windscreen just cracked. He transforms into Torque, summons Magnugiga & performs the End of World, blowing everything away with the beast destroyed for good.