Gyōkaku Kumoi

Gyōkaku Kumoi (雲井 尭覚, Kumoi Gyōkaku?) introduced during The Captain Amagai arc, is one of the clan leaders serving the Kasumiōji noble family. He is also the main antagonist of the arc, apparently replacing Sōsuke Aizen. He is also the steward who handles most of the family affairs. However, when Rurichiyo's father passed away due to illness, he has planned to usurp the head family seat, gathering supporters and creating an assassination squad for his own purposes. He often adopts a smiling and benevolent expression in front of public appearances, which belies his evil and cunning nature. He has his assassins kill off the clan leaders in the noble family who disagree with his views or discover his plans. His main goal is to kill Rurichiyo, the last true descendant of the Kasumiōji family, which he has failed to on several occasions back in Seireitei. He has his assassins pursue her and her bodyguards to the real world, but Ichigo and his friends constantly defeat them. It is later revealed that he wasn't the mastermind behined everything, and was working under Captain Amagai, once Ichigo finds that out Amagai dispaches him.