Beranabus is a very powerful magician that fights demons. He is first introduced in the 2nd book, The Demon Thief, when he goes on a quest to help save Kernel Fleck's baby brother, Art. He is also in the 4th book, Bec, but he goes by the name of Bran. The series main protagonist, Grubistch (Grubbs) Grady, is not introduced to Beranabus until book 6, Demon Apocalypse, where Beranabus saves Grubbs from Lord Loss and pulls him into the world of Demonata hunting.
Beranabus is half demon and has lived for over 16 hundred years. He is the head of the Disciples but does not usually work with them. He hunts the Demonata in their world not his own. He is very straight forward and his work is more important to him than anything else.