Ketamine has produced some pretty weird experiences with 'entities' for me...
I have felt like I have been possessed, which starts off with a swirling mass above my head, which is of interest to me, so I watch it, it descends into one of my eyes, and this feels strange but alluring, so I let it continue. At this point it has not being and I dont see it as an entity, only a part of what is going on.
Then, as the vortex drills further into me and it gets more intense, I realise that it is in fact an 'entity' or other being, and this entity is filling my body with their (evil) soul/being. I become aware of them taking over every inch of my body and infiltrating my skeleton. It is terrifying. And it doesn't go away for what seems like a very very long time.
I also encounter 'good entities', most often when I am lying on my back in the near pitch black (only light being from the LED on my laptop plug) whilst nearing the end of a ketamine trip. The entities appear to begin with as swirling lights, dancing across my body and filling the room with positive energy, they don't feel especially 'different' to me in this state, but as the trip progresses, they calm, and move to the sides of my body, lingering in my peripheral vision. There are always equal numbers, 2, 4, 6, rarely more. They all seem to be undertaking a different task or activity in relation to the trip. They are all though, good and positive and 'helping' entities. I am aware that they are definitely separate to me, and although this is slightly unnerving, I feel okay about it, because I know they are there for good (I am, in normal life, TERRIFIED of ghosts or anything vaguely like that!)
Ive had other experiences of entities on mushrooms and DMT, but im verrrrry tired, so thats for another time
