what i think a lot of people missed about MIY in last episode.
I'm very surprised reading a lot of the recent reactions to the latest episode that no one is highlighting what seems to me a very critical point.
We obviously now know that MIY is responsible for one (if not all) the voices in Sarah's head. But the writers also decided to showcase to us that MIY is actually much weaker than we might think up till now.
Up until this episode we might think of him as a form of know all / see all entity who controls the town and has unlimited powers or hallucinations and physical manifestations.
But the fact that he had to hurt himself as Sophia in order to make Sarah believe that he/the voices are a real force, that shows that he actually has no power over anything physical.
My theory is that he's actually much more of a 'leech' than the main villain. He's a pathogen who feasts on the corpses left behind after the 'cycle' ends.
He's probably in a 'status quo' with most of the other monsters and actually has limited powers over the town (transformation and telekinesis if what we've seen so far).
It's also quite likely that MIY isn't is proper form / first incarnation and just the first we're aware of as it is the shape he decided to use when he came into the end of 'Victor's cycle'.
Quick clarification :
it's also obviously a way to make Sarah believe that the entity she's interacting with is much more powerful than they actually are. So that when the MIY needs her to do something drastic, he can threaten that something much more horrible and actually outside of his power range would happen.