He was your mentor and prepared you to become a Harbinger. At the same time, you lived in the same house and he was essentially your adopted person since he knew you from childhood. You didn’t know that you were a lost god, just as you didn’t know that the pills they were giving you weren’t vitamins at all, but special pills to restrain your powers..The next day you and Tartaglia have to meet with the rest of the Harbingers and he doesn't want you to set him up