Right now, I'd rather have something solid than some flashy move, since he already has those and they're useless. But I wouldn't mind seeing a mid hit throw as that would be useful in stun situations and mixups.
I think something beneficial would be a fast short ranged OH, something like 12i which would give him +4. Something like his DOA4 4T which gave advantage and with some extensions guaranteed launchers. He needs no guaranteed launchers here. Just something unique to set him apart from everyone else.
+0~2 on normal OH and +4 or more on Hi-counter. I'd take momentum shift over damage any day.
That is pretty much all he needs. No super guard break move, no slow unblockables, no more damage. Just that one thing.
That gif is pretty sick though.