Fiends

Fiends are evil inhabitants of the Aetheric Pathways that prey upon mortal souls. The origins of fiends are as varied as their appearances, and no two fiends can ever be considered alike. Even those of the same classification harbor differing dark hungers that they can barely control.
  Some fiends are agents of evil gods like Har-Kuur or Otti. A dark soul who pledged their life to one of them often is reborn as a fiend in death, serving their dark master even beyond the grave. Other mortal souls can be corrupted after death, caught in the Pathways and altered to be a servant. Souls that were once mortal but turned into fiends are referred to as devils. Others are spawned from concepts of negativity: anger, jealousy, misery, and any others. These conceptually spawned fiends are demons: forces of wicked nature. Not all demons serve a god as a result, their nature being one of pure instinct.