Shidou Dairenji

The former head of Twin Horn Syndicate/Bicornis Fellowship and the Onmyo Agency's Spirit Division. He used himself as a core to trigger the spiritual disaster that happened two years prior to the story. In the end, he became a ogre (demon) and progressed into Phase 4-scale Phenomena but later died due to unknown reasons. He is the father of the Divine General, Suzuka Dairenji. When he was alive he was a Divine General nicknamed the "Professor."

[Spoiler] It is later learned his maiden name was Souma and Dairenji was another house he married into. Thus implying blood relations with Takiko. [/Spoiler]

(Source: Wikipedia)