Personally I've never seen or had a "demon" episode up close and personal. However, I used to have, on occasion, the sensation of being held still, while asleep.
I used to have a recurring dream of entering a old victorian buiding and sensing a "demon' on the second floor. I always woke up before I found out what was up there. One night I slept long enough to see the dream to conclusion. The building was a mortuary and the second floor was the work area, marble slabs and all. Funny thing is I have never been inside a building like this.
The recurring dream and the "holding sensations" both came to a halt after I decided to quit the witnesses. I've been in a long term fade for several years and never have nitemares or "scary' sensations anymore.
Any Freudian anaylisis out there.... ????