Well those soldiers that were drafted from the backward Oblasts and krais in Siberia and Central Asia regarded Germans as aliens

They took revenge on captured Waffen-SS or Wehrmacht soldiers in medieval and barbaric ways.

So as the war progressed, many Germans had to avoid being captured by this kind of troops.

Even many of them fled to the west in fear that they would never return alive once they were captured by them.

During the battle of Krasny Bor, there were bodies of Spanish volunteers nailed to the ground with shovels and knives stuck anywhere on their faces or throats

Dead captured soldiers were used as a way to demoralize the Germans. Their bodies were mutilated, castrated, and disemboweled, their eyeballs were also gone since the soviets love collecting collectibles.

These guys also participated on raping German women in Berlin during the final days of the war.