User:Hazama the trolledge

Yūki Terumi was the original creator of the Azure Grimoire and, alongside Relius Clover and Shūichirō Ayatsuki, the Black Beast. After being brainwashed by Konoe, he was forced to serve as one of the Six Heroes who fought against the Black Beast in the First War of Ars Magus. After the beast was destroyed, he was freed from the spell by Trinity Glassfield, due to her affection towards his host body, and he in turn murdered her and Konoe. He was the original owner of the Susano'o Unit armor (which now belongs to Hakumen), and it is assumed that, after realizing he was forever linked to the Master Unit while in the armor, he drove himself out of it - which is possibly why he now appears as a ghost. He was formerly sealed away in the Boundary after Hakumen sacrificed himself to pull him in, with help from Jubei