Board Thread:Questions and Answers/@comment-29521428-20190219111841/@comment-26993961-20190219120512

Nigh Omnipotence isn't an exact level of power, but rather a statement that "this entity is so powerful it would take an all-powerful entity to defeat them". Nigh-Omnipotence can't be "proven" so much as it is a title, a label, give to the strongest beings in any given verse that aren't the omnipotent (in a verse that has an omnipotent entity in it, of course).

Nigh-Omnipotence has to be taken on a case-by-case basis in each verse, since "nigh-omnipotence" is such a nebulous term with dramatically variable levels of power. I mean, since omnipotence is unscalable by any definition and way of looking at it, how do you even know when you're near omnipotence (nigh-omnipotent) to begin with?

So yes, Nigh-Omnipotence isn't provable, but is simply a label given to extraordinarily powerful beings.