The Destructive Spirit, Chooser of the Lie
Angra Mainyu, Avestan for "destructive spirit," called Ahriman in Middle Persian, is the evil pole of Zoroastrian dualism. Yasna 30 describes the two primal spirits as twins who chose opposite paths in thought, word, and deed, one choosing truth and the other the lie. He cannot create life, only counter-create: the first chapter of the Vendidad lists sixteen good lands made by Ahura Mazda, and for each Angra Mainyu casts a matching plague — killing winter, serpents, pestilence, doubt, and lamentation. Snakes, scorpions, and other noxious creatures, the khrafstras, are counted among his works.
The Bundahishn narrates his great assault: leaping from the northern darkness, he pierced the sky, burst into the earth, turned sweet water salt, withered the plants, slew the primordial bull and Gayomard the first man, and brought death to every living thing — only to find himself trapped inside the world like a beast in a snare, so that cosmic history becomes the long process of exhausting him. Doctrine promises that at the Frashokereti, the final renovation, the dead will rise, molten metal will wash the earth clean, and Angra Mainyu will be rendered powerless forever. The Zoroastrian duties of killing vermin and keeping fire and water pure are concrete acts of enlistment on the side of light. In later Persian literature Ahriman became a byword for every tempter; the devil Eblis who seduces Zahhak in the Shahnameh carries on his role.
