If you really do want constructive criticism, I have plenty. For starters...
- Make him f**king defeatable. As he is, it looks like an edgy Mary Sue oc made by a teenager who thinks their parents hate them.
- That bloodthirst is a good character trait. Not that I said "trait" and not "personality". Unless this is a different person and I have not been following this enough, they seem to be very protective of Pixie and tolerant towards allies like DIO and Gabriel. You can play on that. A good character has a developed personality.