Michael at first had started as a stereotype character as you can see by just his loud attire. His uniform at the start of the movie had depicted him an honorable war hero, showing that he would rather pull the trigger for patriotism and a legitimate war. As he started to develop. His character is almost but not immediately rounded as the story had progressed. Michael had the choice to do it. The sound of the train, by the look of it, given him the motivation to do it swiftly. As you can see, the way he had killed both Sollozzo and McCluskey was different than what was expected of him. What can we make of that?

In the comparison to the Heroes' Journey, the characterization between the two characters are much the same, albeit approached differently.