The Nazis implemented various strategies to try and mitigate psychological damage among soldiers involved in their killing units, including Indoctrination and Dehumanization
What did the nazis do to save the soldiers of its killing units from psychological damage?
The Nazis taught their soldiers to believe in Nazi ideas and used propaganda to make the victims seem less human. This helped the soldiers to think that their actions were okay.
They showed the victims as not human, enemies, or dangers to the German people and said their actions were needed for the Aryan race to survive and get stronger.
Soldiers were made to see violence and killing over and over again to make them used to it and not feel as upset about what they were doing. The Nazis wanted to make violence seem normal for soldiers so it wouldn't affect them as much.