One of the many faces of evil, Satannish is a Class Two Demon or Hell-Lord; he rules his own hellish spirit realm populated by damned souls, most of whom were enslaved through bargains they struck with Satannish while alive. Satannish and other Hell-Lords originated as fragments of a mass of dark mystical energy remaining from the battle between Demogorge and the evil Elder Gods; Satannish's development was apparently guided by Dormammu, lord of the Dark Dimension, whom he has long secretly served. Regardless of his origins, Satannish has long menaced humanity in a variety of ways. He sometimes empowers human agents, usually in exchange for their souls or some other service.
Heroic sorcerer Doctor Strange has sometimes invoked Satannish's power, but has never entered the demon's service; he first encountered Satannish when minor mystic Lord Nekron tried unsuccessfully to sacrifice Strange's soul to Satannish in place of his own. Shortly thereafter, a faction of the Sons of Satannish cult led by Asmodeus (secretly Strange's old medical colleague, Dr. Charles Benton) tapped Satannish's power in a world-threatening scheme thwarted by Doctor Strange, the Black Knight and the Avengers. Dying of a heart attack in battle with Strange, a resurrected Asmodeus later tried to win back his life and soul by seeking the souls of the Defenders, but he was defeated and Satannish claimed him. Satannish's subsequent schemes have been opposed by champions such as Strange, Daimon Hellstrom, Luke Cage, the Hulk, the Avengers (who twice fought the Satannish-empowered Hangman) and Hellcat.
Though he once teamed with fellow Hell-Lords Mephisto and Thog to create a temporary Hell on Earth with the unwitting aid of the Six-Fingered Hand (a scheme thwarted by the Defenders), Satannish has long pursued a bitter rivalry with Mephisto, notably during their battles over the souls of Baron Mordo (a fight broken up by Strange) and Satannish's Lethal Legion (the souls of evil historical figures which were stolen from Mephisto and pitted against the Avengers). Satannish ultimately tried to conquer all Hell realms on behalf of his mentor Dormammu, but their coup failed and Mephisto seemingly destroyed Satannish. Since Satannish's demise, a virtually identical demon known as Molgotha has appeared, but how or if he is related to Satannish remains to be seen.