Iiiiinteresting, yeah Matoba would definitely manipulate him if he was tipped off by anything Mahito reacts to or says that makes it seem as though he doesn't view Matoba immediately as a threat to him, and if he seemed as though he might have some uses. Matoba is always in the market for useful ayakashi.....

(If you're mangablind to NatsuYuu btw, I can try to avoid manga-only spoilers if you'd like! Matoba is from the end of Chapter 104 and the anime stopped around the 70's, so a lot of what hasn't been adapted yet is exorcist-centric material haha.)