How Evil Was Commodus？

I have seen the movie “Gladiator.” In the movie there were little different from the actual history. In the movie Commodus kill his own father in order to become a king. In the real history his father was died of an illness during the war with Germanic. I don’t think Commodus was actually an evil man. When he becomes a king, no one taught him how to manage the country. That’s why he didn’t have any support by the senate and peoples. This cause him addicted to become a gladiator and didn’t take cares the affairs of state. Even though he had killed many people that he didn’t trust. We should understand because every king will get rid of the people who are threatening his authority. We should know the actual history rather than just watch a movie. Commodus had brought Rome peace for 60 years and give people time to recover by the war by ended the war with Germanic.