I think you've missed a lot of what made the Nazis so horrific. Everyone knows of the Holocaust, but it's a common misconception that only 6 million people were killed. The real number is closer to 11 million. Six million Jews, plus five million Slavs, Gypsies, homosexuals, political prisoners, etc. were also subject to the death camps and pogroms.

Then you have sheer insanity like the Dirlewanger Brigade where the SS literally got the most deranged and psychopathic criminals in Germany together and set them loose against civilians on the Eastern Front.

There were also many cruel medical experiments, the most famous being Dr. Mengele's experiments at Auschwitz.