One day, Nolan told Mark that he was from a planet called Viltrum and had great strength, could fly and moved at superspeed, leaving Viltrum in order to protect Earth. Mark Grayson was born to Nolan Grayson, a Viltrumite male, and Debbie Grayson, a human female. Mark, annoyed at his parents' display of affection in front of him. After a brief stint with the Teen Team, Mark works with Samantha Eve Wilkins / Atom Eve and the second iteration of the Guardians of the Globe to protect Earth from domestic and extra-terrestrial attacks. A Viltrumite-human by birth, Mark develops his superpowers sometime following his seventeenth birthday and begins training to become his own hero under his father's wing. He is the Viltrumite / Human Hero, Invincible and son of Nolan Grayson / Omni-Man and Debbie Grayson. 2.9 Finding Out The Truth About His Father.
