Sento is selected to represent the country of Touto in a Representative Battle against the country of Hokuto in the next episode of Kamen Rider Build, The Unstoppable Hazard.
Episode 21: The Unstoppable Hazard
Written by Shogo Muto
Directed by Satoshi Morota
In order to stop the fight between Hazard Smash and Cross-Z Charge, Sento (Atsuhiro Inukai) transforms into Build Rabbit Tank Hazard. The overwhelming power stops Cross-Z’s transformation, but is this jet-black Build slowly losing his consciousness and going on a rampage?
The state of the war is growing worse, and Touto’s Prime Minister Taizan Himuro (Meikyo Yamada) returns, and he proposes to Hokuto’s Prime Minister Yoshiko Tajimi (Ryoko Gi) a settlement using a representative Rider from both Touto and Hokuto to fight one another in a one-on-one battle. Yoshiko accepts the “Rider Representative Battle”, and Taizan visits Sento to request his participation in the Representative Battle.
However, Sento now has lost the desire to fight using Hazard Trigger’s fearsome power and refuses to participate in the Representative Battle. It’s at this moment that Isurugi (Yasuyuki Maekawa) appears before Sento. He tells Sento, “You have no choice but to fight,” and presents him with a “secret plan”. What is this secret plan?