Astral Storm
A weakening of the fabric that separates the physical world and the Astral Plane brought on by the will of a powerful entities within the Astral Plane, known as Demons. In the Astral Plane, energy is formed by the collective thought's emotions and beliefs of beings in the real world. Negative energy, known as Malice, can be consciously (or unconsciously) controlled by the imaginations of those who are experiencing intense negative emotions or sensations, which can form into Demons. Most of the time, these storms occur unnoticed by most people, and remain harmless as long as they are contained within the astral plane. However, entities from the other side can temporarily escape into the real world, appearing as incorporeal apparitions, which can be seen and communicate with creatures in the real world. These beings spend their limited time in the real world searching for those who are willing to serve as a vessel for their possession.
Manifestation
Similarly to an area with a lot of Malice, a malice storm manifests as a noticeable decrease in temperature. However, unlike areas that merely have a lot of Malice, the decrease in temperature is much more drastic, sometimes even dropping below freezing temperature, even during the summer. This often causes freak snowstorms, hail, or simply a lot of ice buildup. Thick fog is fills these areas, restricting visibility, and entities can be seen within the fog. In addition, astral storms move around according to the will/collective will of the Demonic entity/entities who created the Astral Storm. These demons will target places where there is more Malice. A Demon can keep the astral storm going for as long as they want to, as long as they have a supply of Malice to use as fuel. If they run out of Malice, the storm ends. Individuals residing within an Astral Storm feel an unshakable primal sensation of fear and will often be plagued by nightmares. Within these nightmares, one feels as though they were pursued by unspeakable Demonic forces. The Demonic forces within these nightmares are themselves the actual Demons who are attempting to invade the world.
Within an affected area, Demons from the Astral Plane can appear in an incorporeal form, most visible within the fog. While the Demons cannot physically damage beings in the real world on their own and cannot directly interact with the real world in this form, they can be quite disturbing in appearance. But just because these Demons cannot directly interact with people doesn't mean they cannot cause harm to them, as they will search for a suitable individual to corrupt and possess.
Since a successful possession can only occur with a person who is willing, they are quite rare. However, successful possessions will allow an entity to exert its power upon the real world and have proven to be quite dangerous. While Demons cannot directly harm anyone on their own, they can invade the mind of a sleeping person, and manifest within their dreams during a REM cycle. Within these nightmarish dreams, the Demon seeks to extract information about others in their search for suitable individuals to possess. It is worth reiterating that the Demon can never harm the dreamer in any way, except psychologically.

This is a very interesting idea of demons entering our world. I love it it's easier for demons to create a zone of their own where there's been lots of malice.Love the detail and the whole idea of it very cool A place where a serial killer did their torturing and killing. When a demon create an Astral storm at location. Would they make the dreams about the killer to seem like he's alive or even take the roll of the serial killer
Good question. I've decided to write another article specifically about the demons, and clarify the amount of control they have over the dreams of a person. The purpose of the dream invasion is to extract information. I'm thinking that most of the time, the demon relies on their appearance and the imagination of the sleeper to create the nightmares, but extremely powerful demons can be more direct in how the dream goes.
when I'm done, I'll edit this article to include links to the demon article.
the article has been finished, and the links have been made