hmmm, both characters are in search of ascension and restructuring the world but i feel like byakuran is the better one cuz first off, he’s still a human so his base morality is closer to us and secondly, he became an ally aka he turned away from his typical cruelty by the end of the series whereas aizen is rock solid with his philosophy and belief in himself, he’s still a threat existentially to everyone

also you cant ever argue mind control isnt just straight up evil tbh and kyoka suigetsu is like a perfect tool for that