Dark Decadus X DarKaiju Warriors: Legions of Vengeance!

(Spin-Off of Kamen Rider Primordial)

In the world of A.R. of both Decadus' world who lost his trusted allies by the hands of huntsmen, and now he took the dark path of vengeance to take over Remnant and destroy the world forever. Then another A.R. world of DarKaiju Warriors who lost some of their crew members and their leader: Alex Jonah alongside Alan Jonah who were executed in prison while hiding in the warehouse. Now the crossover event happened when both Dr. Watts and Kilgore join forces together to defeat their enemies. Now, Dark Decadus met Pyrhha's brother: Pyrus Nikos aka Kamen Rider.....SHOCKER! who wants revenge against Team RWBY and they met Carni-Virgo and his legionaries themselves. They will join forces together to take back what's rightfully theirs and destroy the world for good........and even crossover events!

RWBY owned by Roosterteeth.
Justice League owned by Dc Comics.