Im pretty sure it's just who he is as a person. I find myself quite similar to him in some ways; I feel good when I give someone love and I feel good when I receive love, but it's not like it's only with one person. I wouldn't call it parental love, I'd say it's actually romantic love but because of the lack of love for ourselves and not necessarily understanding of "empathy" (I don't know what to call it) and the usual love it turns out quite... well, fucked up. This kind of love seems shallow and, well, *is* but it's also the way we understand it and feel it.
In any way it doesn't excuse the fact that he was a manipulative asshole of course.
I wouldn't label him in any way, because we don't know what's necessarily going inside his head and the gender he's attracted to. I'd leave it at him being not necessarily mentally well.
True, I wouldn’t call him ace or aromantic though since I’m aromantic, and he seems to love everyone equally to the point that he can’t really love someone, whereas an aromantic person just doesn’t feel the feeling of love in the first place XD (not that big of a deal tho. I can still feel like love for my family and friends, just not in a romantic light towards real people. Tbh, I’m fine with it since I wouldn’t want to be in a relationship lol)
Is Aoi aromantic? Like he I thought he was a jerk at the beginning and although I still don’t approve of his method, I feel the reason he was so chill with this was that he loves everyone equally and doesn’t have any bond to someone that makes them special. They’re all his friends and he loves them but that’s it.