Once a mercenary working for Chryandemus directly in the Founding Wars, he was placedunder Urugal's Son as an aide & bodyguard. When the Hollow Child was mortally damaged in the war, he placed half his soul in Angier (& half his power), making him a Servant of Filth.
Angier seeks to spread the Desecration of life across the world as the God of Filth.