The VOIDRUNNER'S CODEX is coming! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
I would have said you already can use the IH to model OPM feats.
Saitama is a Greater God (I won't spoil why that is, for those not following the fan theory about who all the characters in OPM are). Although obviously the manga doesn't conform with D&D power levels for such things.
He does sneeze and blow most of Jupiter's surface off its core, which I think is something beyond a Greater God and more akin to a Neutronium Golem (and of course that is still not him at full power). But I think I only have those golems around Divine Rank 11 (of 30).
While its one of my favourites, I don't think its at the top in terms of power. I think it might be trickier modelling some of the feats in Bobobo or Chowder. But hopefully I can duplicate every possibility for the new 5E book.