Orastes is a former priest of Mitra, who was cast from his order for delving in black magic. He was the one who found Xaltotun's remains in a subterranean temple of Set in Stygia, and the Heart of Ahriman below a temple of Mitra in Tarantia. He, along with Tarascus, Amalric, and Valerius, brought Xaltotun back to life with the Heart's magic.
Orastes became Xaltotun's apprentice, learning of ancient sorcery which the world had long forgotten. Orastes learned much evil from Xaltotun, but could never become the powerful wizard Xaltotun was due to Orastes' ancestors being clean men, free of the influence of black magic. When Orastes realized Xaltotun's plan was to restore the ancient kingdom of Acheron, he traveled to Tarantia to warn Tarascus, Amalric, and Valerius. He figured out that the only way they could defeat Xaltotun was to steal the Heart of Ahriman back from the sorcerer and use it against him. However, Xaltotun discovered that Orastes was planning to overthrown him, and killed the priest with a special kind of magic dust that choked him.