Couldn't he just, uh, not betray the hero? You know, to avoid his own death
He is going independent from his family, just to avoid getting involved with the Hero.
He is even trying to avoid getting any core characters into his fold (instead going for NPC's who are meant to die), just to not get involved with the Hero.
Though getting that beastgirl is going to backfire for sure, as her death is supposed to make the Hero question about the social situation. But now that wouldn't happen, the Hero won't get character development he was supposed to get.