I think reading about the Kris OCD theory has added another layer of reasoning as to why Kris doesn't want the player posessing them.
It could be that Kris' dialogue options presented to us are actually some of their intrusive thoughts, and while *they* might not act on them, we can. And that is usually the biggest fear of people who have OCD, not just the thoughts themselves but also the idea of acting on them.
OCD itself generally feels a lot like some demon in your brain feeding you upsetting scenarios/ideas. But most of the time you'll never act on them, because a lot of these thoughts are irrational.
Now imagine if you will, having an eldritch creature who can openly view these thoughts as well, and act on them independently of your volition.














