[Enchilada645]

I never really saw the final fight of this episode as underwhelming because it was never a fight between Aruto and Gai.

It was literally Aruto using his strongest form to try to force back and mediate the other two fighters because this new monster is made from a human and not a humagear, and he's worried that Gai going all out on him could kill him.

Not every fight is a clear someone vs someone fight. In this case it was a case of a devolving bar brawl that kept getting worse because the florist had lost all sense of reasoning and gone mad. While Gai's too much of a confident ass to think of the consequences of possibly endangering a human like that.