The key to interpreting the book of Apocalypse is Apocalypse 17:8-14
8 “The beast that you saw was, and is not, and is about to come up out of the abyss and [g]go to destruction. And those who dwell on the earth, whose name has not been written in the book of life from the foundation of the world, will wonder when they see the beast, that he was and is not and will come. 9 Here is the mind which has wisdom. The seven heads are seven mountains on which the woman sits, 10 and they are seven kings; five have fallen, one is, the other has not yet come; and when he comes, he must remain a little while. 11 The beast which was and is not, is himself also an eighth and is one of the seven, and he goes to destruction. 12 The ten horns which you saw are ten kings who have not yet received a kingdom, but they receive authority as kings with the beast for one hour. 13 These have one [h]purpose, and they give their power and authority to the beast.the coinage with images was part of this "mark of the beast" and remember that Emperor Caligula
note the 7 heads, the 7 rulers of the empire
That is some pretzel logic