Why not go straight to Dirlewanger? Fucking real horrorshow and only because he was given practically unlimited power over people despite being widely despised by his comrades and superiors, and he had been relatively harmless during peacetime and even "persecuted" by his own. Also the nightmare of WWI made him so. As explained by the top comment at https://www.quora.com/Who-was-Oskar-Dirlewanger (expand the top answer, skip the other answers and read elsewhere about him during WWII if you want so).

https://www.quora.com/Is-Nazi-officer-Oskar-Dirlewanger-depicted-in-any-movie being an interesting "technical" thread even as the top answer guy tries to whitewash them with just "some war crimes" which was is ridiculous as they hardly ever did anything but war crimes.

People will always be more attracted by stories than reality. They want things that shocks, not boring and “politically incorrect” historical facts. They will rather prefer a horror story of some band of nazi psychopaths who butchered an entire school even tho historically, besides rumors of some unknown eye witness there's no evidence of.

Yeah, except it wasn't a school, it was an orphanage (Christian Orthodox) and the guy can over come here an find the mass grave site near the restored Jan Klimak church. (The witness is also not "unknown", it was a German veteran, and he thought it was "some kind of school" because he had no idea, just a lot of children.) It was also nothing particularly special for Dirlewanger.

And Come and See is hardly "Soviet propaganda", and it's an allegory. It's so much different than let's say an usual Yugoslav partisan movie, the silly genre parodied in Underground. An interesting and even more "religious" Soviet partisan film is The Ascent.