That's why I said you had a misunderstandings of "Human Boundaries" when it was first mention in HxH. From the beginning, it doesn't mean what a Human can do by its own, but what a Human can create and originate. In that sense is why I say it's limited to imagination and that's limited to knowledge.
How about a poll to vote on whether nanika is or not using nen lol?
Wish granted. Now give me your posts. *scary Nanika face*
Well, to me the fact that there does not seem to be a limitation to alluka's ability is pretty strong evidence that this is not actually nen. I guess she does demand payment to everyone but killua however the fact that she does not seem to impose nen at any point nor does she seem to have conditions when pestering points towards something different from nen. Ultimately, the most basic principle of nen is that you can't make things beyond human capacity and alluka healing gon was just that (impossible injuries and an impossible imposed nen).
I believe Nanika uses nen but specialization on a massive scale. Specialization in itself isn't bound to the known rules of Nen they often surpass certain boundaries...Ex..Fortune Telling, Hatsu theft, Mind reading, Nen absorbtion, frankenstine puppets..Nanika is a genie in a bottle for Killua and potential pandora's box for someone else...Members of the Zodiac felt Nanika using her nen to heal Gon. Can't remember any claims to it feeling like something other than nen..So i vote super specialization.
We have no reason to believe nanika imposed a nen on gon. She did the opposite, remove a nen which was beyond the capacities of nen removers and altogether eliminate it (which is awesome considering most nen removers actually somehow take the nen onto themselves and have some condition to actually make it disappear) and healed gon, which was beyond the capacities of medicine and nen altogether too. Nanika basically did something not a single nen eraser has been able to do so far to live up to the name, she actually erased nen from existence.
I'm pretty sure that Nanika/Alluka uses Nen. Every single type of those things (mediums, geniuses, etc.) use Nen subconsciously, so I don't see why it wouldn't be the same for Alluka.
I think "predicting the future" would be something beyond "Human Boundaries", don't you think? Or yet, 100% potency on all Hatsus is something completely absurd and completely beyond human boundaries, after all, no one was shown to be capable of doing something even remotely similar. Both of those powers exist, and yet they still feel "fair", because of their restrictions. Just like Alluka/Nanika.
Well, to be fair the future is not quite written in stone, it can be changed and in fact it was. As for 100% in all categories, it really does not sound like something absurd. Clearly it is not a normal ability however at least it seems conceptually possible and can be worked around to some extent through imposing pledges and whatnot. Also, regarding the fairness issue, it is certainly not the same as with alluka at all. Nanika can grant wishes without any boundaries as far as we know. Even when she pesters the conditions have nothing to do with any imposed nen and it never seems like nen is being imposed at all. Then there is the overwhelmingly gargantuan issue of killua being able to ask for anything at all with no consequences to himself or alluka whatsoever. At least that is what healing gon would suggest as the nen imposed on him seemed to be the direct consequence of giving up all of his potential and future and healing him was beyond what nen and technology could do.