The way I tend to approve of Shedim is... Hm. Mechanically, the Shedite is driving the host around like a stolen car, with occasional Will roll situations if the host goes, "Oh, heck, NO" for some reason. It's just too hard, from a meta-game standpoint, to make it more complicated than that.
Role-playingly, though, having the Shedite's player speak in terms of
leading the host around... that's more satisfying. And if the GM can spare the time to make the host sometimes think things that disturb (or please) the Shedite, all the better!
http://www.io.com/~arcangel/GamingWa...U/myINIOU.html is a slightly silly crossover of In Nomine and IOU. There is a Shedite of the Game (Mellor) as one of the players. The player in question did Mellor brilliantly, I think -- a mix of unmitigated steering, descriptive stuff about the host interactions, soothing with tentacle kisses... (Not to mention the arguments with one host about who she found sexy. Danny, Malakite of Judgment, was one. Asmodeus was another. Mellor was... unpleased.)