User blog comment:Varzan Deodinm Beldinm/Most Powerful Semblance?/@comment-25555436-20150108204355/@comment-23790511-20150108210725

Aura is a manifestation of the soul, not the soul itself. But regardless, a villain that could cut through the strongest defense a human in this universe has like butter would still be insanely powerful. I'm not saying there should be a character like that all, but it's still a possible like any other semblance until they say otherwise.

I agree though. A power like that has to be shown in a way where the character who possessd an Nullification semblance is both balanced and well-written.

Akira is something I watched recently, and Tetsuo in that movie was insanely powerful. But he was young, egotistic, had an inferiority-complex, and ultimately that power extended to where he transmuted matter into biomass which ultimately led to his downfall.

They could balance a character with an nullification semblance by making it so that if this hypothetical villain used it too much, his/her own soul and aura would decay in response to how much he/she used it.