I know there is a concern regarding the current attack potency of Hezi Piposh, but as it is now,
it seems his attack potency is considered as 516,644.24 joules, whereas
Suisei's attack potency scales above 896,500 joules, so Suisei is 1.7× stronger. Considering how
Piposh was able to tank a grenade exploding while it was touching him, he is probably tougher than he is strong, since his strength stat comes from only kicking down a door. Piposh's lifting strength is ranked as Peak Human, while Suisei's is Class 25, so Suisei could use that to her advantage.
I think Piposh's versatility is more consistent, as his profile has plenty of evidence of him succeeding at illogical actions, superpowers and fourth wall breaks. His regeneration and immortality would also be helpful in the battle. Suisei has her own versatility that I still have no idea about in terms of when it would be in character for her to use them. Considering how
Piposh can replace himself if he dies, it means Suisei would need to incapacitate him rather than kill him.
Based on my assessment, I vote for Hezi Piposh winning the battle, because even though he is weaker, he is difficult to take down, and as far as I'm aware, he would be more likely to perform cartoony shenanigans that would give him the advantage.