Immediately after the Rapture, the Antichrist makes the covenant with Israel (Daniel 9:27). The False Prophet will seek to unify the religions of the world. He will not ask them to worship differently; but, to tolerate each other and not proselyte from one religion to another. They will not worship a single generic "god" as some have supposed; until the Antichrist demands their worship in the middle of the Tribulation Period.
There is a power struggle for world leadership in the first 3 ½ years, with the Antichrist gaining dominance. (Revelation 17:10-11) He gives the 10 Kings of Revelation 17:12,13, their power and divides the world governance into 10 areas, or provinces, and gives each ruler responsibility for a province. They are to carry out the directions of the Antichrist and the False Prophet, which they do.
A. The "seven mountains" are not the "Seven Hills of Rome." ; but, seven kings, as the Angel explains to the Apostle John. "And there are...should be "they are" from the Gr. "eisi." (Rev. 17:10a).
B. There is no "Revived Roman Empire; but, the Antichrist rules a world empire, meaning "global." The Roman Empire at its greatest extent only covered 4.4% of the world's land mass.