The scarlet colored beast is Satan.
Satan is not any of the seven kings, nor king eight.
.
King eight is the beast king, formerly one of the seven (forthcoming king seven to be exact). He and the false prophet when Jesus returns get cast alive into the lake of fire.
Differently, Satan will be bound and cast into the bottomless pit.
The angel having the last plagues shows John the harlot seated upon the scarlet beast.
And there came one of the seven angels which had the seven vials… So he carried me away in the spirit into the wilderness: and I saw a woman sit upon a scarlet coloured beast, full of names of blasphemy, having seven heads and ten horns (Revelation 17:1, 3)
Then in verses 7 and 8, the angel continues describing the scarlet beast the woman sits upon.
And the angel said unto me, Wherefore didst thou marvel? I will tell thee the mystery of the woman, and of the beast that carrieth her, which hath the seven heads and ten horns. The beast that thou sawest was, and is not; and shall ascend out of the bottomless pit, and go into perdition: and they that dwell on the earth shall wonder, whose names were not written in the book of life from the foundation of the world, when they behold the beast that was, and is not, and yet is. (Revelation 17:7-8)
Your error on the beast is just as myopic as your failure to discern that the seven heads are renamed seven kings initially.
The scarlet beast is the same as the eighth king in verse 11, affirmed by the detail that
it “was, and is not,” too. The beast is cast into the burning flame in Chapter 19 and is with the false prophet when Satan is also cast there, too, in 20:10.
The scarlet beast IS NOT Satan.
And lastly, John is taken to the future, our time, to witness the judgment of the harlot Babylon, insomuch as the angle with the seven last plagues shows him these things.
Again, how is it that a
future mortal man as the antichrist “was” before a first-century Roman emperor in your view as a futurist?