Seemingly on par with Ahura Mazda or slightly inferior.
Ruler of the Divs,god of death,god of evil, personifying deceit and chaos;former ruler of the creation
Leader of the Divs; Summoned by Armati
In Conan the Barbarian: Flame and the Fiend (2000), a sorceress named Armati summoned a Demon named "Angra-Mainyu", seemingly as a reference to Ahriman's other name.
The Demons' profile in the Marvel Zombies Handbook (September, 2007) described this character as an "extradimensional demon". The update of the profile in Official Handbook of the Marvel Universe A to Z #3 (July, 2008) add a mention of Ahriman among the death gods (mentioning him as "Daevas/Persian Gods", without relating them (the death gods associated with Earth being closer to class 2 demons, while the extradimensional demons are class 3 demons). Ahriman was also developed in Thor & Hercules: Encyclopaedia Mythologica (July 22, 2009).
Thor & Hercules: Encyclopaedia Mythologica mentions the Persian Gods as the Yazatas (the Daevas being the Indian gods), though they are technically the creations of Ahura Mazda. It is unclear whether Ahriman's mention in the Marvel Zombies Handbook is correct (and Ahriman, and presumably Ahura Mazda are to be considered), or if this is an error, on its own or related to earlier versions of the Persian and Indian pantheons' origins and relation.
Journey into Mystery (Vol. 2) #1 (July, 1972) (Usurped by or confused with Malik Tous) Giant-Size Conan #1 (June, 1974) (Mentioned) Thor & Hercules: Encyclopaedia Mythologica #1 (July, 2009) (The Yazatas' profile)
Anthony Flamini, Greg Pak, Fred van Lente, Paul Cornell, Kevin Sharpe
Angra-Mainyu; "chaotic spirit", "destructive mind" (translation of Angra Mainyu);
Possibly Ohriman,Oh Rahmen