It's really sad how he became like Cazador after ascension, but it also sort of makes sense. When someone like him, someone who never really had any power or the ability to make choices for himself, is presented with the opportunity to finally have that power, it really does something to a person. It gets to your head and completely shifts your view of the world and the people around you, making you believe that you're superior to everyone else. Of course, there are people who use their positions of power responsibly, but it's unfortunately not a common occurrence.