While I'm comfortable being singular at the moment (although I will always have various imaginary characters flitting about in my head with voices and opinions of their own), I'm also comfortable in the knowledge that one of my tried and true coping strategies for stressful or wildly disparate situations is to revert to a plural identity in order to manage each situation in my head. This is why I will say "we" occasionally when talking about any applicable era, or revert to "we" when exceptionally tired. (And in cases where it does start to seem like it's a party rather than a single person, there's no problem if you care to explicitly address whoever happens to be chattering, or explicitly address the Collective ("you" and "y'all" and "guys" all work) -- also no problem if you don't happen to pick up on it and address us as normal. When things are plural there's sort of a switchboard/hub effect so external parties never have to worry about routing.)
Second portion of backstory for the new kids: From 2001 to 2005, I lived with a college friend and her small son (known as the Little Fayoumis). For many of those years, I shared child-rearing responsibilities, having approximately the authority of an aunt. A strict aunt. This was his ages four to eight.
Inevitably, the LF started making reference to an imaginary friend. That was all well and good, until he started misbehaving and blaming it on his imaginary friend.
I was about to take him to task for just that, doing stuff and blaming it on his imaginary friend, when I ran smack into a contradiction in my chain of logic. How could I be internally consistent if I had multiple personalities myself while scolding the LF for doing something himself and blaming it on his imaginary friend when he might either merely have an imaginary friend or he might have an additional self-facet or other form of multiple inside his head? I had no way of knowing for sure without having way too deep and possibly leading of a conversation with him, and in any case I was presenting myself to him with once face only (no matter which facet was operating at the time). I was fairly convinced that he just had an imaginary friend who was the product of a lively imagination, but I couldn't be an ethical multiple myself without considering the possibility.
I had to sit down with myself and think about it for a while before I came up with a solution that I found acceptable. In the end, I couldn't fault him for having and talking about an imaginary friend, whether it was solely an imaginary friend or something more integral to his own identity. That was not the problem. The problem was that no matter whose idea it was, he was physically carrying out actions that he had been instructed not to do.
So that's what I addressed. I can't remember the details of how I did it, but I made it pretty clear that when anyone told the LF to not do something, or that he must do something, that any and all of his invisible friends were included in that directive. Furthermore, as the party in charge of body operation, the LF was responsible for making sure that nothing was done that was not supposed to be done, by anybody; if he failed to keep his friends in check and they did something that he wasn't supposed to do, they would all be in the time-out together.
Things worked out after that.