Zaoumaru Zaitsuhara (財津原 蔵王丸, Zaitsuhara Zaōmaru?, portrayed by Kenji Matsuda), known as Zanki (ザンキ?) is the oldest of the four main Oni in the series. Being the seasoned vet, even Hibiki saw him as a superior, even though Hibiki had once trained Zanki in the use of Taiko. Zanki was first mentioned in episode 5, when after defeating the Douji of a Bakegani, him and his disciple Todoroki were forced to retreat after being attacked suddenly by the Bakegani itself.
Read more about this topic: Kamen Rider Zanki, Zaoumaru Zaitsuhara