This is the first time I've heard about this, not quite the way I've ever understood it. I thought Jesus was supposed to be on the Christian side? Obviously I'm not anything close to a theologian.
"..In ISIS’ interpretation, the figure of the Mahdi, or “the rightly guided one” will appear to lead final battles against the Western infidels, called Rome, in northern Syria before the end of days. After the day of judgment, only those who supported the Mahdi will be saved. The Mahdi will appear after the establishment of an Islamic caliphate. (Medieval caliphs, attempting to gin up support for their own battles against the Christian crusaders, claimed to be the Mahdi in the past.) In some of the prophecies, Jesus descends from the heavens to assist the Mahdi in his battle against the infidels, who are led by an Antichrist figure.."
https://news.yahoo.com/the-doomsday-ideology-of-isis-192945938.html
"..In ISIS’ interpretation, the figure of the Mahdi, or “the rightly guided one” will appear to lead final battles against the Western infidels, called Rome, in northern Syria before the end of days. After the day of judgment, only those who supported the Mahdi will be saved. The Mahdi will appear after the establishment of an Islamic caliphate. (Medieval caliphs, attempting to gin up support for their own battles against the Christian crusaders, claimed to be the Mahdi in the past.) In some of the prophecies, Jesus descends from the heavens to assist the Mahdi in his battle against the infidels, who are led by an Antichrist figure.."
https://news.yahoo.com/the-doomsday-ideology-of-isis-192945938.html