Ahriman (アーリマン, Āriman) is a unique summoning to Jashin. This creature, a fiend no less, serves as the mimicry of Angra Mainyu, the evil spirit (equivalent to Satan) in the Zoroastrian religion and also the true identity of Jashin.. His name means "destructive mentality". Zarich and Tawrich, the twin fang-like blades its caster wields, are the Daevas (rejected gods) of aging and hunger.
The summoning requirements for Ahriman are unknown considering Jashin rarely ever summons the creature, nor are his abilities known well enough to be feared. What is known however, it that is serves as the perfect bane to those who rely heavily upon both taijutsu and ninjutsu, leading to the assumption that he utilizes barriers for both offensive and defensive purposes.