Ragibach is 'one of the 13 great demons of Hell' who is currently possessing the body of Cosette Weinberg, the firstborn daughter of Ludwig Parvis and Rowena Weinberg.
History[]
Ragibach was first seen in Chapter 92 when Rowena Weinberg summons the demon and desperately makes a deal by explaining that she wants the people who destroyed her life to be punished. As a result of this, Rowena's soul was taken by Ragibach in exchange for being summoned but not before the demon asks Rowena the name of the child, to which she replies that "the child's name is... Cosette."
Before Ragibach had been summoned and was about to possess over Cosette, it was revealed that the real Cosette died in Rowena's womb when she was trying to run away from a group of assassins hired by Simon Edinburgh.