Source: TW
The middle Iranian text AyAdgAr I zAmAspIg or zAmAsp nAmag presents an interesting Iranian apocalypse paralleling the coming of kalkin. Parallel to the H scenario, it presents events leading to the coming of the saoshyant when the Arabs, Turks & “Romans” will be overthrown.
It also posits a cosmic conflict between mithra and aeshma daeva paralleling that of ahura mazdha and angra mainyu. In the former battle a certain demon know as vadag-jav-kAr will join on the side of aeshma daeva. His name means maker of bad grain. It seems to be a late surviving Iranian memory of the dAnava kuyava slain by indra in the H tradition: shuShNam pipruM kuyavaM vR^itram indra yadAvadhIr vi puraH shambarasya | as you O indra, slew shuShNa, kuyava, vR^itra and rent the forts of shambara.