Mark Grayson is the son of Omni-Man and Debbie Grayson. Born a Viltrumite-human hybrid, Mark would attain his powers during his last year of high school, and begin training with his father to become the hero known as Invincible. But, after finding out his father isn't all he seemed to be, Mark works the second iteration of the Guardians of the Globe to protect the entire galaxy from the threat of the Viltrum Empire.