Daddy
... why joining her peerage when it wouldn’t bring him any significant boost? 1st, he is a king! Becoming someone’s servant should be beneath him. 2nd, he is an archmage in the making, with genius potential and capabilities. He doesn’t need the drawbacks of becoming a devil (light/holy, politics). He can probably find a way to take sacred gears (boosted gear) for himself to further increase his power. 3rd, he can quickly build his own strong faction with the binding ability and the previous 2 abilities.