Demons are evil immortals who feed upon magic and life and inspire dread and fear in mortals. They delight in inflicting suffering, spreading corruption, and, of course, destroying all that is good. Most demons were once mortal. Not all demons are sentient: various animals have been transformed into demons, for instance.
Origin
Most demons were once mortal creatures, but have been transformed by their conversion into demonic beings. In order to become a demon, a creature must be infused with magic to its core, and as the existence of non-sentient demons suggests a creature's wishes are irrelevant to the process. Willing or not, a creature can be changed into a demon. Such a transformation alters the affected creature on a fundamental level and typically leaves little or nothing of that creature's original personality, but there are exceptions though.
To this date all demons are evil.
Powers
All demons are immortal. After becoming a demon, it gains control over magic with the sheer force of their will, similar to sorcerers.
Demonic Classes
There are several classes of demon, such as Daemons or Balrons (both Lesser Demons), and Greater Demons (or simply Demons), which are god-like in power.
Many Lesser Demons are summonable if the caster has enough skill, though it takes additional power to bind him to his will. Most (Greater) Demons are simply too powerful to be summoned by common casters, less alone controllable, but although almost impossible it has been done before.
