Nazis are bad. The occult can be messy. Put the two together, and you have a threat for the ages.
This is a trope with no end of Truth in Television
to it. Even ignoring the embellishments, you've got the Thule Society, the adoption of the swastika (a mystical symbol of Eastern religions) as Nazi party standard, and Hitler's pursuit of the Spear of Destiny
- Indiana Jones. Period.
- Hellboy was summoned by a Nazi ritual, but quickly brought into American hands.
- Return to Castle Wolfenstein has you breaking up a plot to resurrect an ancient Germanic warlord as an unstoppable superweapon for the Reich.
- The graphic novel The Life Eaters posits an Alternate History where the death camps were part of a massive necromantic ritual to bring the Norse gods into existence on the side of the Nazis.
I'd also be up for broadening this trope to include any depictions of Nazi superscience and unconventional warfare. Maybe we could call it Stupid Jetpack Hitler