Dissociation strikes me as the most "forced" compliance. And with such an override comes stupidity. It's basically striping away the person who was there and replacing them with a dumbed-down puppet. I can only imagine that enough of that eventually starts permanently damaging the host's lucidity. There's a similar dynamic with the Reapers of Mass Effect. (The fast method will reduce the victims to a drooling vegetable within weeks. In the slower process leaves marks, but doesn't kill the mind entirely.)

I know it's not cannon, and that collar she usually wears Guards against impregnation. But it wouldn't shock me at all if over time she eventually embraces demon hood to throw off her chains entirely.

Agreed, quite the comic! I suspect she really is going to end up his servant. A strangely befitting end to the comic's overall story.