That's bull. The German people weren't taken over by Satanic forces. Enough of the population became convinced that what the government said was in the best interests of the country as a whole was more important than what was good for any individual. Enough of the population became convinced that the experts knew more about how to solve the problems of the country than the people did, and if they just turned responsibility for solving the problems over to those experts they wouldn't themselves have to worry about having to go to the trouble of thinking about complex problems like that.
Modern day examples of that mindset are all around us. Their solutions to the supposed crises of Healthcare and Global Warming spring to mind. Just let the statist experts come up with the solutions and everything will be dandy for everyone, they say. And just like in Germany, a LOT of people in current America buy into it.
Hitler and his henchmen were possessed. You can either believe it or not. The occult nature of Nazism has been well-documented. The German people didn’t have any say in it after 1933.