Aotabo

Aotabo is called "the degenerate priest who wears the iron blue robe" and is the physically strongest yōkai in the Nura household. Long before joining the Nura Clan, Aotabo was a warrior monk who was arrested for having committed a severe transgression and who had killed a thousand warriors. On the verge of being executed, a holy man's words changed his ideals and he decided to live for the sake of others. The holy man told Aotabo that if he continued to kill people, he would become a monster, and the way to regain his humanity was to save one person for each of the sins he had committed.