I Was Modified by Aliens from the Start

Any Stories About Someone Pretending to Be an Alien and Flying a Spaceship to Earth?

Any Stories Where the Male Lead Has No Feelings and Is a Modified Human?

Mechanical modification, flesh-and-blood modification, genetic mutation, or radiation mutation are all fine. I want an utterly insane protagonist. The person who modified him thought he was dead and abandoned him. Whether he has a System doesn't matter.