The Blue-haired demon is the character we are first introduced to in the City of Bones. He is trying to get past the bouncer into pandemonium. He is carrying a spear with him which appears harmless with a glamour. He is suduced by Isabelle and is lead into the storage room. Here he meets Jace and Alec who tie him up. Jace is about to kill him when Clary steps out and tells them to stop. While Jace and Clary talk the demon gets free of his bonds and attacks Jace. The end of the fight results in the Demon being killed.