How is that one still alive considering both halfs of it were stomped on, at least one side should've had the core, because if that's destroyed/stomped/etc., it should immediately die.
Didn't he give them all a paste-core-strengthening injection waaaay back at the beginning? After a hundred pages, I've lost track. Or maybe I'm thinking of some other epic story.
Maybe the paste core is tough enough, and the Reimu is gooshy enough, that when you apply pressure to one half of her, the core slips over to the other side. Kinda like here post #21594, only with pressure instead of with an anal claw probe.