Yes, many. Alexander VI was a famous example. He fathered 6 children while he was a Pope.
He bought his position, hired assassins to kill other people, had incest, he was a very famous bad pope indeed.
Pius XII reputation comes from his lack of action rather then from anything he did personally. He was the pope during Hitler's reign of terror and didn't so much as speak one direct harsh word about the man who was slaughtering millions. Hitler was Catholic after all and never antagonized the papacy (which is apparently the one way to get excommunicated.) His continuing refusal to say anything against the Nazi party lasted throughout the war with lame excuses being put forth behind the reasoning as to why this was.
He claimed he would not decry any individual atrocities publicly and when faced with the Holocaust he merely claimed there wasn't enough evidence it was actually happening.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.