http://www.kr-hcy.com/articles/imam-mehdi.shtml - for the "prophecies" of Mehdi:
"An army will come from the East towards Arabia. The East here refers to Khurasan, (Afghanistan). They will pave the way for the establishment of Imam Mahdi's kingdom. This army will carry black banners. Nothing shall stop their onward march, and eventually they will plant their flag on the soils of Jerusalem."
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The term "MEHDI" is a title meaning "Guided one". The Mehdi is a normal man who is going to follow the true Islam. His name will be Muhammad and his father name will be Abdullah. He is a descendant from Ali and Fatima (daughter of the prophet Muhammad) so he will be descendant from al-Hasan or al-Hussain or both. The Mehdi will be very just and his capital will be Damascus. The Mehdi is NOT a prophet but he is the final Rightly Guided Khalifah. The Mehdi will lead Muslims to a great victory against the Sufyaani and the Romans. This great war or Armageddon. It will end up with a great victory to Muslims against Romans after six years. Muslims will take over their capital Rome (this can be any city). In the seventh year, the Dajjal (antichrist) will appear and a greater war will start between his followers and the believers for 40 days (longer that usual days) and will end when 'Eessa ("Jesus") will come, slay the Dajjal along with his followers. All remaining people will convert into Islam. Peace will pervade the whole world.