Or maybe the Devil just gave them a roadmap.
Likely.
They could have summoned several demons and asked for the best land to carry out their extermination of innocents. I’m totally serious. Hitler likely struck a deal with the Devil and in exchange for his soul, power, but the thing when you traffic with evil is that you only are able to do evil. So Hitler killed as many Jews as he could and threw in others as a bonus. There’s no other reason that he was so able to find just the right evil people to do those horrific crimes. No way is there any natural explanation for how he managed to find Heydrich, Himmler, Goering, Goebbels, Mengele, Hess, Rohm, all the other monsters who oiled his rise to power and helped him unleash such a bloodbath. I sincerely think that Lucifer brought them up straight from Hell and gave the monsters I just listed human bodies and ordered them to help Hitler as much as possible.