Angra Mainyu or Ahriman, in ancient Persian religion and books of Zoroastrianism, is the God of Darkness, the eternal destroyer of good, personification and creator of Evil, bringer of death and disease. His Name means "fiendish spirit".
Meaning and Purpose
He is seen as the personification of evil, When Ahura Mazda created the heavens, Azi Dahaka sprung into the sky like a snake, and in opposition to the stars formed the planets. Both Ahriman and Ormazd were offspring of Zurvan, who had vowed that the firstborn should reign as king. Ahriman thus ripped open his mother's womb, and Zurvan pronounced that he should rule only for nine thousand years, after which period his twin brother should reign in his place.
Ahriman's chief weapon was concupiscence, through which all that was his should be devoured, even his own creation. There was a female counterpart of Ahriman, called Az, and it is said that when Ahriman saw the righteous man he swooned, and lay in a faint for three thousand years, until the 'accursed whore', Jeh, awoke him and defiled men with her destructive spirit, introducing fear, jealousy, lust and greed into man.
Ahriman lives in darkness, in a place where all those who do evil go to after their demise (Hell) and his symbol is the snake.