This is an experience that both me and my older brother have had to live through for the last 16 years of our lives. We have both experienced the same phenomenon whilst both being in the same area or in separate counties.
I suppose its best to start with the first encounter we had with the thing that could only be described as a black mass. Me and my older brother had been sharing a room since I was born and were therefore used to each others company by this point. We had both been allocated one bed each in the bunkbed. Mine was on the bottom whilst my brothers was above me. The night in question was when I was 3 and my brother, Reece, was 7. The day had been regular with us both going along with our normal routines until bed time in which we both promptly fell into a deep sleep. I suppose it was around 1 in the morning when we began to realize that there was a strange presence in the room. The probability of both of us waking up at the same time is so small but this time it happened and we both looked at the doorway that was located at the end of our bed.
The white door was always closed when the light was turned off in order to ensure that we could get a full nights sleep, however, as we both looked across to the door, it began to swing open and a figure moved through. It was not a regular movement as it was more hovering than walking as there was no movement in the shoulders at all. As we both stared, it turned and walked next to our beds and first stared at the top bunk. I was at this point petrified as it seemed like as this thing came closer, whispering could be heard and it got louder as it approached. It was a constant stream but all of the whispers were mixed, I couldn't make heads or tails of them. Then it looked down at me. I have never been so scared in my life, its eyes were like a red I have never seen since. It was like staring into a bright red flame. It then moved its head down and almost touched me before I shouted and screamed. Once I had done this, it stood bolt upright and moved towards the door at lightening pace.
Since then, both me and my brother have noticed its presence and it has often visited the both of us in our sleep. More recently, I have started to be able to make out a word from the whispers but it sounded like the being had said them. It had said 'Welcome'. I still have not heard anything else yet but that same word repeated over and over. However, this is not just restricted to when we are sleeping as both of us have experienced some kind of interaction with it outside of the bedroom. It has, on more than one occasion, defended both me and my older brother from things like bullies or certain other mishaps. A perfect example was that my older brother was chopping up some veg and looked away. The knife was going to cut his hand when the being appeared and stopped it with its own. Both me and my brother were startled to say the least but it seemed like it wouldn't let him hurt himself.
The same instance has happened to me but in a more intimate way. I get into fights quite a lot due to the fact I'm very formal and opinionated, however, when the fists start flying its like I am not in control of my body. I know that several people call this the red mist and that it happens to everyone but I am clear on what I can see and hear but my body moves on its own accord. When this happens it feels like my body becomes very tight and cold. I believe this is infact the thing possessing me to ensure that I do not get hurt in any fashion. I also had a crash half a year back, the airbags did not go off and my seatbelt snapped. I should have gone flying through the windscreen but instead I felt two hands hold me firmly back to ensure I did not get hurt. When I looked up, I caught a glimpse of its face before it faded out and saw its teeth and it seemed to be smiling.
Both me and my brother are puzzled by this and are starting to wonder whether this is an old family member trying to protect us or whether it is infact some sort of demon from the other world that is playing us.
I think that you should be cautioned no matter what at it being evil, but at the same time due to my experience with Jack that this being isn't necessarily evil.