GodOfGreedAs
just turn essence of blank & essence of archmage into his origin.it also aligns with his behaviour till now.mc always seeks to grow in power one way or another. so he is highly compatible with blank origin. Also mc has an almost unnatural yearning for arcane knowledge as well as a talent for recreating spells from other verses as well as a monstrous mana regeneration which is literally archmage essence. Additionally if mc also has essence of the king, it would be best.
I will agree with the 7 deadly sins since he does embody most of them and their potential is immense. You could like have him awaken the 7 deadly sins and then he could delegate it to his wife's not only increasing their power but it also makes him stronger as he could get their power and experience multiplied by several times as they get stronger so lets say his wifes get +1 in strength he could get +10 or more making him stronger faster and getting all the abilities they developed without side effects as he is the origin of the 7 deadly sins
Void is cool but it is not possible to make it origin instead how about MC's origin being WORLD fragment which gains consciousness because of MC's transmigration and its only goal is to reach the top of hierarchy like outer gods. It will also explain MC's craziness for gaining power his good and bad deeds as he aggregation of all good all sins too . just a suggestion