Billy is introduced as a young, pacifistic priest of the Ethos, who runs his own unaffiliated orphanage in the Aquvy region. As an Etone, Billy is charged to protect the world from the Wels. Billy has a strained relationship with his father Jesiah, but puts up with him for the sake of his little sister, Primera. Billy wears a long, drab blue cloak with a big pale green ribbon on his chest, with a pale green shirt underneath, brown trousers and matching boots. He also has light grey hair.