The Thanasioi were adherents to the heresy preached by Thanasios, a puritanical preacher in the western region of the Empire of Videssos. The heretics used the Phos' Creed just like the orthodox believers, but preached that the materialism in the world was the work of the dark god Skotos, and thus a quick life followed by death and ascension to Phos' light would be their salvation; thus they rejected the hypocrisy of the orthodoxy who preached for Phos while living lavish lifestyles. In contrast to the orthodoxy, the Thanasioi preferred asceticism; some of the more fanatical believers starved themselves to death in order to hasten their meeting with Phos.