Sersi is a human race, a race of ancient aliens who lived in secret for the eon. Sersi, not the other Eternals, favors live and self-interest with the help of an army, and works together as a museum curator, while defending them from the Deviant threats. The ability to manipulate the things that make her different shapes if she retouches the subject, gives Sersi an opportunity to talk with her fellow Eternal, Ikaris, and help recruit them for a last mission.
