Mary Sebastian Grayson is a Viltrumite-Human hybrid superhero Lady Invincible, the daughter of Nolan and Debbie Grayson, the paternal older half-sister of Oliver Grayson, and the bestfriend of Eve Wilkins/Atom Eve. Born as a Viltrumite-Human, Mary would ultimately gain her powers at the age of 17, and begin training to become a hero under her father's mentorship. She is a brave, competitive, kind, and noble hero who stays true to her values, wouldn’t hesitate to kill if her family is threatened.