Kamen Rider Build Episode 21 is titled “Hazard Won’t Stop”, directed by Kazuya Kamihoriuchi & written by Shogo Muto. The curtains open to a new battle. The beginning of a new war.
Sento who had used the Forbidden Item “Hazard Trigger” transforms into Black colored Build called Hazard Form. If Takumi Katsuragi’s words are right then Kamen Rider Build will lose his Will if continued to fight in Hazard Form. In this way, the Item which was used to stop Ryuga strikes himself back. Kamen Rider Build loses his will during the Fight. After the end of the fight with the Three Crows, there was an unbelievable sight spread in front of him.