There's an old saying that goes "behind every great man is a great woman", great typically meaning "someone who becomes famous and/or makes tons of money".
Therefore it could also be said that behind every evil man is an evil woman, which has been proven to be true by awful human beings like Hitler, Stalin and Kim Jong-Il.
Eva Braun's political influence on Hitler was minor, and Stalin's wife Nadezhda Alliluyeva didn't have anything to do with his political actions either, so it's debatable whether they were evil or not.
But Ko Young Hee was said to have had a huge influence on both Kim Jong-Il and her son Kim Jong-Un, serving as an advisor and pulling the strings from behind the scenes.
Osama bin Laden's favorite wife Amal al-Sadah, on the other hand, accompanied her husband wherever he went, and she even took a bullet in the leg during the raid that claimed bin Laden's life.