Sakyou is the owner and leader of Team Toguro, though he's best known for being the true architect behind both the Rescue Yukina and Dark Tournament arcs—he simply used the team as puppets for his own purposes. None of the other characters really caught on to this. He's an extremely wealthy man who built his fortune through a lifetime of high-stakes gambling, and he uses a signature move to win: betting his own life. It works most of the time because people fold when they realize he's serious, but he's been called on it five times. One of those times was against the Black Book Club, a group he used to belong to, and the last—which also happened to be the final rounds of the Dark Tournament—was the final time he ever wagered his life.
Sakyou is typically calm, collected, and intelligent, though his evil side bleeds through in how he carries himself. What makes him disturbing is his history: unlike his siblings, who all became respectable civil servants, he went off the rails. He developed an obsession with blood and gradually escalated from dissecting frogs and fish to cats and dogs, and finally to humans. That appetite for violence eventually led him into the gambling world, where he thrived.
At some point during his gambling career, Sakyou joined the Black Book Club. It was there that a crucial moment happened: the former Spirit Detective Shinobu Sensui stumbled upon one of the BBC's experiments. The group had forced humans to slaughter demons pulled through portals from the demon plane, then had them bathe in the blood. Sensui was horrified. He killed all the humans involved and began to seriously question the nature of humanity itself.
Content compiled by AnimeList.moe from publicly available sources.
