He seems very neutral to me; after all, he is in essence the creator of everything in space. I think, if we were speaking in D'n'D terms, he would be a Chaotic Neutral. He finds satisfaction in creating celestial bodies, but the beings within them he feels less about because they couldn't even begin to perceive how irrelevant their lives are. They think they can control their creators, and while the Targonians trick him into being able to be controlled, he spites them for it (as seen when he killed the Pantheon far before the Pantheon we know [named Atreus prior to becoming an Aspect of Targon]).
I do think it's very sad however, that the Targonians tricked him like they did. They made it so that every time he disobeys, one of his creations (essentially his children) dies. They may be stars, but to him, they are everything he ever loved.
But anyways, yes, he is definitely in neutral morals. Evil morality would be void creatures like Vel'Koz and Cho'Gath. Good would obviously be people like Shen or Ashe.
I never liked Ao Shin. I actually really hated it, and hated the stupid hype surrounding him. Aurelion Sol was a vast improvement, and the personality and story behind his character is one of the best of the newest champions. They've put in so much work. Have you watched his interactions? He has over 110 special interactions with just about everything in the game. And through one of his interactions, it's confirmed that Taric is an Aspect of Targon (hinting at his rework that's coming up after the release of Aurelion Sol).