Corey was a bit of a macho jerk who, unknown to himself, was manifesting as a mutant with an avatar trait. He accidentally invaded Bast's space in a dream and savaged one of her people. Bast gave him a choice of serving her as her Paladin, or dying. Not much of a choice, really. Corey's family did not take this well, and she eventually had to leave them for her own safety.