We read about various stories like Hansel and Gretel about witches that wanted to eat children. Were such stories like this pure fiction or was there a basis of truth of those?
If there was an andrenochrome appetite 150 years ago among the elites, like there is today, slavery would have been the simplest source to set up a steady supply of blood to these vampires. Just grab say you've sold a dozen slaves or their children to an unknown buyer from another state. Who was really keeping track?
It seems much of the opposition to ending slavery came from powerful individuals in Europe who shouldn't have had any any horse in that race.
Just putting that out there.
Almost, the person who delivers "the one good punch" is very important. Cortez was uniquely qualified. The people were waiting for their gods to return and Cortez showing up during an eclipse as well as the impression of their ships, armor, feathers, boom sticks, pale skin and many colored eyes and hair made Cortez a god kin contender against the Aztec's own claim of being descendants of the gods.
We have Trump to deliver "the one good punch" instead of Cortez, but the concept is the same. Trump by today's modern social value system is a contender and our Aztec overlords are terrified.
The only is issue is minimizing local support for their regime and undoing the cultural capture of minds before delivery of that punch.