Killbus (キルバス, Kirubasu) is the main antagonist of Build NEW WORLD: Kamen Rider Cross-Z. He is the former overlord of the Blood Tribe who transforms into Kamen Rider Killbus (仮面ライダーキルバス, Kamen Raidā Kirubasu). He also initially took on the appearance of Sento Kiryu and transformed into Kamen Rider Build (仮面ライダービルド, Kamen Raidā Birudo) before preferring Satoshi Kakizaki (柿崎 悟志, Kakizaki Satoshi) instead. Killbus was the ruthless ruler of the Planet Blood whose lust for conquest led him to destroy