I'm thinking we're already close to the end of the simulation. If you can imagine yourself as anything, you would start to lose any sense of justification for retaining your sense of self, whether mental or physical. Because reality as defined becomes a competition of all minds that can change reality, everything falls into flux and nothing stays the same. Everything becomes meaningless and you stop thinking in any rational manner (because there's no reason to and trying to bring back the pre-change reality is just as easily overwritten by another).
Unless the MCs hold onto their sense of self (Probably kept alive by their friendship and love), the only route they have is going insane.