when regan was in pre posession where was the demon? would it leave and wander off and come back? I mean the bum who said to karras needing a change do you thing pazzuzu was there looking on? also if regan was exorcised in pre posession state bofer the demonic entity completely took over, would she get worse before she got better??
No Pazuzu really had nothing to do with the subway scene. That scene was to show Karras struggling with issues of faith, turning his back on the bum as if it were an intrusion. Pazuzu spoke in the voice of the bum later as part of its mind game, just like when it spoke as Burke Dennings, or Karras’ mother, etc.
But who can say what would happen if? I dont think there are too many scientific accounts of “demonic possession”.
I agree with SLAM234 here – I’ve always believed Pazuzu yanked that subway moment from Karras’ mind and used it to mess with him once their paths crossed.