What is Cato's personality in the Hunger Games?

Cato's personality is very sadistic. He seems to enjoy the Games and it can be assumed that he Volunteered for them. He uses a sWord to fight and is very brutal. In the books, towards the end he seems to start to show feelings for clove, either for actual feelings or for the capitol. However, in the movie it seemed like him and Glimmer were getting close before she died. So besides those two, he usually has a very sadistic attitude. But towards the end, he shows that he is just like everyone else. Wanting to live and scared.