Killbus

Killbus is the king of the Blood Tribe and the main antagonist of the Kamen Rider Build NEW WORLD: Kamen Rider Cross-Z movie. He is the older brother of Evolt who comes to Earth following his brother's demise in search of Ryuga Banjou.

History
After the World of Build was merged with the main Kamen Rider world to create a new world, Killbus arrived in the new world and copies the form of dancer Satoshi Kakizaki. Taking a Build Driver from Sento Kiryu, Killbus obtains the means to transform into his Kamen Rider form, Kamen Rider Killbus, which is even stronger than Kamen Rider Evol. Killbus plans to restore the energy of the Pandora Box and use it to destroy the entire universe.