Angra Mainyu
Zurvanism is a hypothetical religious movement of Zoroastrianism in which the divinity Zurvan is a First Principle (primordial creator deity) who engendered equal-but-opposite twins, Ahura Mazda and Angra Mainyu. Zurvanism is also known as "Zurvanite Zoroastrianism", and may be contrasted with Mazdaism.