Frankly I think people are getting too hung up on specific usage of the term "duality" without considering further nuance. Like, if you are a monad that unites everything into a single essence devoid of separation, then we are talking about an entity that is purely
simple in the mereological sense, meaning that they entities with no composition (i.e have no smaller, more basic "parts" making them up). More accurately they'd be
infinitely simple, not just with respect to spatial or temporal parts but to metaphysical parts as well, such as, say, predicates referring to them.
In the case of such an entity, plurality in any manner is by definition strictly forbbiden, because to introduce a multitude of features is to say that a thing can be broken down into smaller, constituent parts able to be analyzed isolatedly. So if you say that in a thing there are doubles, or triples, or quadruples, or whatever else, then that thing has composition in some level and as such is not perfectly simple anymore, and thus not really something that satisfies the above condition of lacking separation and unifying everything into a single essence.
Mind you, though, this isn't exactly the same as, for example, "Two opposing states, A and B, are true simultaneously." In such a case, you'd still be acknowledging that A and B are distinct attributes that this object somehow just holds at the same time because of some paradoxical nature of theirs (For example in the thought-experiment of Schrodinger's Cat, where the cat in the box is deemed both dead and alive until observed). The above case is more like "There is no plurality or delineation between A and B to begin with," so, for example, a perfectly simple being doesn't have a set of attributes, but
is those attributes, and neither are these attributes truly distinct from one another.
So, yes, I'd say that a being like that is, for all intents and purposes, Transdual, and to reject it and similar things just because it doesn't explicitly mention the word "duality" is pretty baffling to me. I'm relatively more "Eh" on the matter of if verses happen to have more specific schemes than that, though. Like, if the cosmology was based on triads instead of dualities, or something like that, and a character then transcends that. And obviously, the above also isn't the same as simply encompassing or being one with the universe, since both can still involve a character whose nature is a plural, composite one.
As for the rest:
In fact, I don't think on this wiki or outside of this, that would be the general assumption. Nonduality isn't a state that is typically is uniquely characterized by nothingness / lacking things.
I never claimed that it was. I just used that as an example of how lacking or generally standing outside of certain features would mean you are unable to be interacted with by powers whose function is to interact with said features, much like Soul Manipulation is useless if the character it is being attempted against has no soul at all. You could replace "Existence" and "Nonexistence" with whatever else you find convenient.
As for the other part of the response...
Transduality doesn't lack existence or nonexistence, though. Lacking it would mean "is it existent" has a truth value of 0 (false). However, a transdual character definitely wouldn't have a truth value of 0. It would have a different truth value altogether (neither 0 nor 1). The conclusion that this other truth value would behave as if the character had a truth value of 0 is unjustified.
That's not really what I meant with the example. What I was specifying is that a character is in a state where they are neither existent nor nonexistent, or speaking in the language of your argument, one where both propositions ("X exists" and "X doesn't exist") are simultaneously false, not some situation where "X exists" and "X doesn't exist" each have more possible assignable values than "True" and "False." I am very willing to bet the former would be immensely more commonly found in fiction, generally speaking, and it is something we already deem a valid example of a Transdual state if the above exchanges are anything to go by.
That just completely fails to address my argument, as characters with NEP don't get those nature types just for being non-dual at all. We demand statements or feats from that with the same scrutiny as for transduality.
Nature Type 3 explicitly states that showings of being completely unaffected by attacks on the specific aspect are required.
Nature Type 2 does not explicitely require such, but that is because not just any non-dual state is required, but specifically a nondual state of nothingness. We are talking about characters that do not exist, not even in the ordinary binary state of nonexistence, but instead in an even deeper sense. As the page notes such characters would of course often have transduality. After all, affecting an aspect of a character that behaves nonexistent will usually be impossible by regular means. However, those aren't random nondual characters. They need specific showings of a nature of nothingness for this, which go beyond basic nonexistence. Not all nondual characters have showings of such nature. (not even all transdual characters would have NEP Nature Type 2)
Are you saying that Nature Type 2 requires no statements or showings of uninteractability because the nature of the power, on its own, already implies as much? If so, I fail to see how that actually addresses KingPin's point. Their argument, from what I gather, is that Nature Type 2 does not for instance require that a character be transcendent over both existence and nonexistence, just that they lie in some state that is not the former, but not the latter, either, "absent" with respect to both.