It's hard to say since he isn't flaring. If you could get one of him doing that that would greatly help. So far he looks like a super delta or a halfmoon.
He's very cute, love his color! Looks like a super delta to me, he looks like he's either a tail biter or has some minor rot on his tail, just keep an eye on that!
I actually think his tail is fine, just doing that zigzag pattern I see in fancy betta. I think it's a halfmoon/feathertail trait, but dont quote me on that