Just like Corrupted Beings, Demons are also corrupted but not as much as Corrupted Beings. They were probably created by a Demon Sorcerer or just formed in nature. Their hides and remains can be made into weapons and armor.
belligerent, evil demons (which are unplayable) are formed when humans are completely corrupted and taken over by dark magic. Another variety of demons, which can fit into society to an extent, have simply been born demons. (Apparently, the Evil genes are recessive.) Half-demons are the offspring of humans and demons. (Alcohol plays a big part.)
A Demon may be a: