Suikotsu

Suikotsu (睡骨（すいこつ）, "Sleep Skill/Bone") was a member of the Shichinintai. Like the others, he loved carnage and killing; however, unlike them, he had a split personality. This personality was that of a kind-hearted doctor, who may have been the original personality until a traumatic event caused the birth of his other, more bloodthirsty, personality.