Demon

A demon is simply a second highest level of soul development. There are only 7 "real" demons, but there are some demons which have bodies (e.g. Casper) (those are called demi-humans).

The 7 Demons

 * Spiritus Glutton (Latin: Soul Devourer), the demon of, eats souls to turn them into souls.
 * Spiritus Clavis (Latin: Soul Key), the demon of, possesses people to help them release their full potential. Chief Darius is -elemental and possessed by Spiritus Clavis, so he's more heroic than he would normally be.