1 John 5:19

Humanity was put under the rule of the divine council/watchers (Deut 32:8, Septuagint and Dead sea scrolls say "sons of God," later Masoretic gets it wrong and I think tried to cover up fallen angels were ruling over us) as punishment for the Tower of Babel where a giant Ziggurat was built to worship various gods in hope of prosperity and a global system.

Psalm 82 lays out the judgment of these fallen "gods" as they helped mankind develop weapons of war, systems of usury (Babylonian chaos system, aka the beast system), they will now die like men and be thrown into the lake of fire.

All of that I got from Dr. Heiser's Naked Bible Podcast, finishing up his series on Revelation and it's miles ahead of anything else I've ever heard, he demolishes Dispensationalism and points out no eschatology system gets it all right, much of Revelation like:

The Two Beasts are referring back to the symbolic chaos monsters of Leviathan (beast that comes out of the sea in Rev), and Behemoth (the other chaos beast of the land). These beasts are served at the marriage supper of the Lamb (I think Isaiah gets into this) representing chaos and death being consumed/destroyed forever.

The Two Witnesses simply represent all of God's people. The final abomination of desolation of the temple is the desecration of the Christian church (as we are now the temple, see how messed up most people's theology is thinking it's talking about a 3rd temple in the political state of "Israel"?).

The Mark of the Beast also likely only symbolic of which is you are loyal to, although it likely does man Christians will be shunned from society, but no actual marks, just as in the OT those who "bore the name" and put God's word on their foreheads, it was symbolic.

Irenaeus (2nd cent ad) believed 666 was referring to the Titans (as they are kind of a mixture of man an beast; as it's of a beast, but also the number of man, as Jonathan Pageau gets into - The suprising symbology of 666) who are locked away and seem to be released in Rev 9:1-3, so it's probably not Nero, but no way to know for sure.

So John is describing the climactic conflict and defeat of the beast chaos system that’s ruled over mankind since the Tower of Babel where all the nations united against God and were cursed.

In God's mercy, even though all of humanity deserves hell for Adam's sin all of mankind at Babel, with most still rejecting Him today; Jesus still came to rescue us, and we killed him, yet He still offers grace. Grace upon grace.