Thread:AeonChronos/@comment-25106472-20190806120112/@comment-7517569-20190807182800

As I said, the rules of the Persona universe are laxed and heavlily dependant on dramatic needs, so we cannot get an answer that would be correct, just a bunch of hipothesis that would make sense, but lack any real evidence (And the universe tends to contradict itself a lot, if you try to look into it, so even if you got evidence, we're bound to find evidence against it somewhere else).

That said, your question makes little sense. If you mean the situation I presented where the Persona adequates to become the Interdimend's user Persona, then it's not. The "user" itself is no longer them at that point, their body is just an Avatar for the Interdimend User. The user's real mind is pushed to the back of it's brain, something like being asleep, (though a coma may be more adequate).

We have seen this kind of control, albeit it was on Tadashi's Persona, not Hashino's, and as far as I (And most of the fandom invested in the lore) am concerned, are two different universes altogether, so I'd think twice before using Joker as an example.

The closest I can think of would be Sho Minazuki from Persona 4 Ultimax, he had two personalities and depending on which one was active, he held a different power. The same could theoretically apply on this context, where the user aquires a Persona when under control, and loses it when awaken. Though how the exact mechanics of that would work, in theory it shouldn't, but hey, if you wanna make it work, here's a tip:

Nyx's consciousness, the one that births shadows (And therefore Personas) is described in the P3 Club Book  as "Wave-like", so you could in theory apply some Wave Theory to it, if you interprit it as H-waves (though you're bound to find some compatibilty issues between the two universes, as you might expect). If we do this, then the Interdimend user's Soul (In Persona terms, a Soul is a consciousness), is inhabiting the Persona User's. Kind of like a Genom.

Hope this helps.