Fujiko Etou

Fujiko Etou is the current head of the Etou family the head of the girls dorms at Constant Academy and the only person who understands Akutos current situation. Her older brother the Etous previous head was killed after failing a mission causing Fujiko to become the new head of the family though for unexplained reasons she kept her brothers revived head which is kept in a jarlike container filled with fluid. She is the leader of an underground movement that uses black magick magic for evil purposes and plans to use Akutos demon powers once he becomes Demon Lord for her own purposes. Source: Wikipedia