Thanks for the feedback :)
Things are kind of balanced on the easy side if you find a good approach currently; would some settings be helpful maybe? Perhaps that, some additional things to ramp the danger up, and a limit on teleporting away.
That's all difficulty stuff though. Combat wise, hm. An idea that comes to mind that's based on a feature I'd like to add (specifically possession/multiple souls in one body) is being able to use possession attempts to take some characters out of combat temporarily (or longer) as they're busy having a soul struggle instead; possibly other things like that. Perhaps fun but not an improvement, heh.