Will the Mahdi lead Muslims in the Great Battle (Al-Malhamah Al-Kubra) between Muslims and the Romans, and what is the evidence for that?

There is no explicit text stating that the Mahdi will lead Muslims in the Great Battle against the Romans. However, it is confirmed that the fight against the Romans will occur at the time of the descent of the Messiah, and the Mahdi will be present during the time of Jesus, peace be upon him. It appears that he will be their leader in prayer and in jihad, as he is the one behind whom Jesus son of Mary, peace be upon him, will pray. The hadiths have shown similarities in the descriptions of the Messiah and the Mahdi. It can be inferred from some hadiths that the army that fights the Romans is the army of the Mahdi.