Erin Danua
About
Just like she did with Josephine, Erin has showered Tates with love, maybe even more. He, who had lived since ancient times, had been looking for a successor and had considered Tates as the heir to the throne.
However, he was betrayed by his trusted disciple and hesitated at the last second when he should have delivered the final blow.
(Source: I Killed the Player of the Academy Wiki)