Ok, they seem to be pretty common experiences. In the video report they mention how different cultures even have a term for this e.g. China = Gui Ya. I find it interesting that a malevolent presence, or at least perceived to be, is a common theme in these experiences. This could be due to the person not being able to comprehend what is happening, and fear taking over..

I find when I have a nightmare, whatever I fear most at that moment within in the dream usually appears. I wonder if this is similar with sleep paralysis? Your inability to think logically in this situation leads to panic and being confronted with your greatest fears.

Does anyone have a theory on the dark presences and why they are so common among people in this state?