Keyman

The titular superhero who protects Rockville. He has the strength to lift cars, the ability to fly, and his skin is tough enough to withstand machine gun fire without even a single scratch. Although extremely popular with the citizens, he's noticeably violent, often punishing criminals more than necessary and appearing seemingly unfazed whenever they die.

His real identity was Clint McCoy, the terminally ill son of a Rockville billionaire. He was turned into a Keyman at age 9 and died at the age of 14.