Whether they be demons, devils, daemons on some other creature, demons is what they are most often referred as.
These are the creatures that live in our realm but in other “dimensions” and which are responsible for the runic bindings, and for making the “afterlife” that resembles the Christian concept of hell.
Demons we know about currrently.
Ankroptic - a demon who is regarded as being either stupid or a child, and who seeks followers on earth, so he can gain more power, there is a cult formed around him. He is not one of the Demon’s that sits upon the council. He known as a demon on rot and decay.
Darconofv - the leader of the demon council and the demon responsible for creating the runes and the Trils.
Hasmital - another demon on the council who is the only one of the demons who gets to have followers of him come to his realm when after they die.
Bispithuel - a demon mentioned in Dewey’s spellbook, that states that “agitated summoning” did not work upon it, but no other information.
Kor Ma Ka - another demon, details are very limited.
There is another but I can remember their name but they are the servant of Darconofv. Nesfender (??)