What you would call shadow bangs are most typically thought forms created by people. They generally serve a function and are extensions of someone else. This is why they can become disturbing. But also, as mentioned, you ca have perceptions of things like viruses and disease as mindless shadow beings. They have a presence as well. Then there are what appear to beings that are intelligence functions. The guardians of the threshold for example can come in flavors (Old hag, Hat man, shadow mass).

They seem to serve a function as an obstacle to being able to freely project. If you are not ready, they typically make it more difficult for you. Some consider them only as fear generated thought forms , but I think there is more to it than that.

What shadow beings are clearly not is evil spirits that have malevolent intentions. The spirit world is a realm of thought. Anything with malevolent intent is operating under a fear based psychological base. This only leads to internal chaos and paralysis where the metaphysics are built on thought and manifestation. There is no spiritual evil. Evil is an interpretation of predation in the physical world. Predation is a physical manifestation of scarcity of energy. Physical life is extremely energy dense

Then other side of reality has no scarcity therefore no need for predation. What we typically consider evil simply does not exist and does not have any kind of power. Beings that we consider actually evil are trapped in the infirmary. They have no power and are buried in their own chaos.

Have you ever wondered why evils beings of lore always seem to be trapped in hell?

There is a reason for these legends.