Duo is an extraterrestrial robot from outer space that was created to destroy anything evil and to seal the deadly Stardroids inside of him. However, he's an absurdly strict, hypercritical, unstoppable Knight Templar with zero tolerance of anything he sees as evil. He came here on earth after Dr. Wily to execute him for his evil. And with his oversized left fist, along with his powerful energy attacks such as the "Righteous Fist" or "Virtue Meteor"... good luck on stopping this "justice" bot.