Every person, every individual, is unique. This is the greatest glory of the universe - that each creature living (and dead) is different from all others. It's obvious, then, that the multiverse centers around the self, or so this faction would have everyone believe. "The world exists because the mind imagines it. Without the self, the multiverse ceases to be." Therefore, each Signer is the most important person in the multiverse.
Without at least one Signer to imagine it all, the rest of the factions would cease to exist. Better be nice to the Signers then, because they just might decide to imagine a body right out of existence. Don't think it can be done? Maybe not, but then a basher's a fool to take the risk. Lots of folks disappear without a trace, and more than a few are enemies of the Signers.
A lot of folks don't accept this idea. After all, they point to their own feelings and emotions, their own self, as proof the Signers are wrong. And the Signers simply claim to have imagined it all. What others feel and think isn't real; only what the Signers feel is. So exactly who is imagining the multiverse? That part even the Signers don't know for sure. One of them is, but they can't agree on which one. The safest bet is just to fall in with their faction, because any Signer could be the source of everything.