Kamen Rider Series S33E08 - Chance Meeting VII: Trump Card Ninja

Keiwa's older sister, Sara has been kidnapped by a Knight Jyamato. Despite his injuries, Keiwa is re-motivated by Ace not to give up on saving Sara, while the latter apologize for using the former during its first round. After finding Sara's whereabouts, the four surviving Riders transforms in front of her. While Keiwa protects Sara, her hand accidentally touches her brother's Tycoon ID Core, revealing an unexplained terrifying past that Keiwa did not know about.