Aæšm in the poetic gathas and the Avesta is the arch-demon of “wrath, ruin and devastation.” Aæšm comes from the root aēš or aæš “to set into frenzied motion, chaos.” In the Zoroastrian sacred lore aæšm is the opposite of sraôš “melodies/songs of the gods, divine music, inspiration.” In the poetic gathas “the diabolic powers daævás rush into aæšm “frenzied mania” to sicken/corrupt all that is ahuric/godly in mortal’s existence, (Yasna 30.6, 3rd rhymed verse line.)
The Old Norse eisa “go about recklessly, be rowdy” is a cognate. Lithuanian aistrā “violent passion, rage,” coming from the root *heis is a synonym. Eris the personification of “discord, strife” who supposedly initiated the Trojan wars in Greek mythology can be compared with aæšm. In Greek mythology Eris is the opposite of Harmonia, and seems to share many collective attributes with demon aæšm in the Avesta.
Interestingly the Zoroastrian arch-demon aæšm takes a whole new identity in Jewish mystic literature. Hebrew Ashmedai was borrowed from the Persian/Zoroastrian arch demon aæšm. But, the (Hebrew: אשמדאי Ashmedai) is no longer the dreaded arch-fiend of Zoroastrianism; but the king of the Jewish demons (Pes. 110 a.)
An aggadic narrative describes Ashmedai as the king of all the demons (Pesachim109b–112a). In the Zohar, Ashmedai is represented as the teacher of Solomon, to whom he gave a book of extraordinary knowledge (Zohar Lev. pp. 19a, 43a; ib. Num. 199b, ed.) Ashmedai is also mentioned in Talmudic legends, in the story of the construction of the Temple of Solomon.
According to Zohar; many Jewish demons study Torah, and will not harm a human Torah scholar. Ashmedai himself is said to ascend to Heaven to study the Torah.
While there is NO doubt that Zoroastrianism has exerted a great influence on other faiths in areas of apocalyptic literature, and the ultimate battle between good and evil. Yet, it is also irrefutable that so many original gathic and Avestan concepts often took a WHOLE and entirely DIFFERENT identity/meaning in their new Judeo-Christian context.