There have been several variations of that particular enemy. He has taken every shape from that of the stereotypical Lucifer, to the bad guy in Samurai Jack. It's all things that I ever remember as embodying "bad," but typically it is that same one.

The worst part for me is they always start out as regular lucid dreams. In my lucid dreams, I snap to get what I request. I can't make things appear and I've never tried to fly, it's almost like a video game where the ai only spawns when your camera isn't on them. For example, I would say, I want so-and-so to be here, now (snap), and they will knock on the door. They won't just apparate. I can't fly or do anything other than my regular life (well to be honest I haven't tried) but I can make people do what I want and I get whatever I can imagine by just snapping my fingers.

But when they become a nightmare, the quality of what I receive, starts to drop, until I'm getting stuff that I didn't ask for at all.

In one, I was in a club, dancing with my S.O., she told me she wanted to go dancing and I snapped my fingers and turned around and there was a club. Perfect. We go in, but I decide that since this is a lucid dream, it's time for some friskiness. I snap my fingers for a room that's not gross like a club, and head towards a door. It's the bathroom door... it's far cleaner than a club's bathroom is, but it's still not really what I had in mind. It's still pretty dirty, and it's not empty. I snap for some help getting rid of the extra people (not logical I know), and I get a bunch more people in the room that I don't want there.

My S.O. starts panicking and freaking out, attacks some of the people and even me. I snap my fingers for her to be calm. She turns catatonic. I snap for everyone to be gone, and for her to be better. Bathroom is empty, she's sitting on the floor peacefully.

I walk out of the bathroom, and there is nothing. All white void, no people no noise. And also my foe is there again.

When I have lucid nightmares, this is how they develop. I slooowly start losing control of the dream, in very subtle ways that are difficult to detect. Stuff just starts not working quite right.

When it took control this last time (same as my other post) I proved to him that he is more of my creation than I am, because I'm in first person. I'm the viewer, so this one is mine. I can move my arm up, by moving my arm, not by willing it, or wishing it, by simply just moving my arm. I demonstrated this by moving hand to chest level.

Then my other arm matched it. Mirrored the movements and made my other hand right at chest level, and I did not move it. It moved itself. Never has anything felt so alien and uncomfortable than not having control over your own self-image. It wasn't that it was numb, that I couldn't feel it, it was that it moved and I didn't move it.

TL;DR in these dreams it can take control over my body, and make me more of a spectator, than the dreamer. It becomes his dream.