Code Geass

Lelouch is a Britannian prince hiding in occupied Japan, and he hates the empire that killed his mother and crippled his sister. A strange girl gives him Geass: the power to make anyone follow one absolute order. He becomes Zero, a masked rebel leader, and starts pulling the whole occupation apart. The hook is that the power has rules, and the fun is watching him bend a situation around those rules. It looks like a normal mecha show until you notice it is really about a smart, vindictive man who keeps raising his own stakes until he cannot stop.