What will happen after Mahdi? Until when will his sovereignty last?

Mahdi is the last mujaddid (reviver) (1), he will continue his rule till the Day of Judgment. We learn this from the following hadiths:
"A group of people from the Muslims will remain on the Right Path and continue until the Day of Judgment to triumph over those who oppose them."(2)

"The last part of this group will fight Messiah Dajjal (Anti-Christ). (3)


We know that Hazrat Mahdi will fight Messiah Dajjal. So the spiritual leader of this group that will fight for the right path will be Hazrat Mahdi.

If that is the last group then the leader is the last, too. So there wont be any other mahdi or mujaddid after Hazrat Mahdi. His deep-rooted and permanent works and services based on the Quran have the strength to enlighten and meet the needs of his age and ages after that.

Those coming after him will be only his helpers and executors of his program.

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(1) Mujaddid: What is stated in the hadith is the scholars that will emerge at the beginning of each age and clean the religion from things added to it later and from superstitions. The above –mentioned hadith is : "Allah sends a reviver of the religion in every one hundred years." (al-Hakim, al-Mustadrak, 4:522; al-Munavi, Fayzul-Qadir, 2:281, hadith no: 1845.)
(2) Muslim, Iman: 247.
(3) Abu Dawud, Jihad: 4.