If you've seen this film, can you please clarify a few things:
1) Is Regan possessed by Satan himself or just some evil spirit?
2) When she is finally exorcised, where does the spirit go? I know it's still inside her in The Exorcist 2, but supposing there is no sequel, where would it have gone?
3) How did Father Karras manage to get the spirit inside him? And if the spirit DID leave Regan to possess him, how is it 'dormant' in the girl in the sequel?
Any help is appreciated! I've only seen this movie 2 times and the first time I saw it, it was freaking scary.