Sometimes, the pot and the kettle actually ARE both black. Hitler and Stalin eventually hated each other and went to war ... that doesn't make either of them good.
Actually, Hitler and Stalin got on rather well after the signing of the 1939 non-aggression pact. They agreed on the partitioning of conquered Poland, the Soviets shipped lots of ore & materiel to the Third Reich, etc.
Stalin was absolutely gobsmacked when the Nazis invaded the USSR, and felt a keen sense of betrayal. How could his colleague Adolf do such a thing?