Weird Question: What if Mizuchi possesses Sumireko?

We know Mizuchi can possess others. But... can she possess Sumireko?

If you're asking me, my answer is Mizuchi just possessed Sumireko's doppelganger body and not the latter's actual body. Because Sumireko's actual body is in the Outside World.

In a way, maybe Sumireko can wake up once her doppelganger is or is about to get possessed by Mizuchi thus escaping her.

That's all I can think of for now.