I like how the main villain's early actions make it understandable how someone could choose to follow him without personally desiring the end of the world. I mean... nuclear disarmament? Good start, buddy!
What if there were a story where some mighty immortal, trapped under rocks for literally thousands of years, woke up, got to see the world
And had an overall positive reaction at first? Like,
They saw cars, and were impressed with the speed at which a machine, unaided by any beasts of burden, could move
And they saw trains, and got excited about trains, because trains are exciting
And then planes. Wow, planes. Planes! If I were that old, and had been asleep that long, planes would blow my mind.
And then someone tells them that smallpox isn't a thing anymore, and oh my good golly gumdrops, smallpox isn't a thing anymore! Again, coming from that far back in history, I'd be blown away.
So they're impressed by that, and by the scale on which people live now (because Cairo ca. 1984 is much, much bigger than Cairo back when there were still working out the issues in pyramid-building), and at first this mighty, immortal ruler, this ancient world-ruler, is just walking around, taking in the sights, and they're thinking, y'know, this is good. I like what you've done with the place. A+ work, kids.
And where they go from there kind of depends on the tone you want to set. Do they remain impressed? Do they decide that humanity, while it has progressed, still needs them at the helm for some reason? Do they see something, some darker side to this advancement, that convinces them that they need to do something big to change things?
Can't really get into that last one without discussing what it is that would convince them that the world needs re-making, and I'm not in the mood to make it something ridiculous like Adam Sandler movies (though, to be fair, "burn the world" is a perfectly understandable reaction to Adam Sandler's financial success), so... yeah. Fun thing to think about.