Void is the home of creatures feeding on emotions and feelings of mortals. Occasionally, those so called Void Daemons find a gateway to the material world and begin to feed. Feed on souls. The are all but invincible, for they grow stronger consuming the anger, hatred and fear of those who oppose them. Void Daemons don't have material bodies, and they look like made of white vapour. Here'you have an example ;] They are those bad guys in world on which I am working.