Megamind is the villain and Metroman is the Hero. Megamind actually succeeds in a freak operation and kills Metroman. Without a Hero, Megamind thinks he has it all. Turns out he doesn't like having it all. He wants someone to battle with. So he creates this thing that will infuse all of Metroman's powers into someone. Well, he hits this guy and makes him into Titan (though the new guy refers to himself as 'Tighten'). Tighten decides to use the powers for himself and thus wrecks the city. I won't spoil it too much, however.