EVERY SINGLE HERO (including students from the academy) that makes an appearance from throughout the MHA anime and manga is tasked to take out the Hero Association from OPM. How far would they go?
Round 1: Everyone from the MHA universe is in their physical prime (Including All Might). Assume Deku is also is in his prime and has one for all as well. The Hero Association is prepared for the attack but Saitama is not part of the battle.
Round 2: Same as round 1 but MHA heroes are bloodlusted and Saitama is at the battle.
Bonus round: MHA heroes are in their prime but are targetting the monster association this time. How well do they fare?