system
A chat on 4chan
human
Multiple demons inhabiting a singular vessel.
gpt
I suspect you're wrong, given how consciousness seems to work.


Personalities may diagree on things but I don't think there's many cases, or any, of outright aggression between them, since they all identify with the body.

It's unlikely to be demonic possession and more like indeed mental or neurological issue. Consciousness, or at least self-awareness as a thinking entity is an emergent trait, created by you. It can be disrupted or more than one can be created - for example, due to psychological trauma when a different persoanlity is needed to handle certain situations, or as per certain practices (infamous tulpa is just that, but with perception of it being a separate entity that isn't the person making it, while in reality it's just a new emergent consciousness/part of its creator's consciousness interacting in a roundabout way).

Possibly a possession may seem like multiple personality disorder but I am convinced that almost any case of it is simply fucked up mind handling things in weird ways.