True godly is basically Regenerationn from the most primary level of destruction. In Demonbane, Nyarlathotep regenerated even after being oblitered by Elder God Demonbane more than four hundren million times. Perhaps, the only way Nya can truly die is if Azathoth awakens to which then, she can't regenerate or obviously she may be erased by Yog-Sothoth, a more abstract, more primary being so I'm sorry but NLF does not apply here, and claiming something is NLF when it comes to higher tiers is fallaicious in itslef. If a character displays this type of Regenerationn regardless of tier, they have it fairly, if it is portrayed consistently.
I'm sorry but bringing up multi-valued logic also does not change how this transduality works. I say this because this is a concept, in which how it is used, mirrors the context of nondualism in metaphysics and/or spiritual/religious practice. That is normally how it is used in fiction. This version of transdualism applies to the underlying changing reality or ultimate unchanging reality found in Buddhism or Hinduism (Brahman, Anatma) basically concepts that involve nonduality that cannot be expressed in human terms.
Using the
Cthulhu Mythos as an example, you have such a cosmology:
1. Three dimensional reality with humans
2. Endless chain of dimensions
3. Dimensionless space
4. Ultimate Void of the Outer Gods
5. Yog-Sothoth (all existence
and nonexistence, Yog is a nondual entity and nonduality is a lowly concept to Yog)
6. Nyog Sothep and Magnum Tenebrosum (an even more
primary existence and
absolute nonexistence. Both can either be a more primary version of Yog or even more abstract)
7. Azathoth (after waking up/dismantling the illusion, because Azathoth dreamt up some tranacendent existence and nonexistence or two beings who are likely beyond such concepts, and the omniscient totality known as Yog-Sothoth, it must be the absolute primary "existence").
True Godly regen is where you can regenerate from either 5 or 6 (6 being a very rare or extreme case) while High Godly regen is where you can only regenerate from 3 or 4. You will generally see true godly regen in works that have a composite hierarchy, as a standard hierarchy of only dimensional space and then dimensionless space is not enough in most cases.
That's basically, the difference between the two.