Sersi is a fictional character, a Marvel Comics superheroine and an Eternal. Sersi is a fourth generation member of the Eternals, an evolutionary offshoot of the human race. Sersi is the daughter of the Eternals Helios and Perse, and was probably born in Olympia, Greece, some time after the Great Cataclysm that destroyed the continents of Atlantis and Lemuria, during an extended ice age known as the Hyborean Age. At a young age, Sersi differed from her fellow Eternals in her desire to live amongst humans. It was during her time in ancient Mesopotamia that Sersi first met Captain America, who had traveled back in time. While Sersi still had the appearance of a child at this time, she was already thousands of years old.
As a member of the race of superhumans known as the Eternals, Sersi has the standard abilities of Earth's Eternals, though she has focused the majority of her power into transmutational abilities and passed it off as illusion or magic over the centuries. Sersi's psionic ability to rearrange the molecular structure of objects is far greater than that of any other Eternal; the limits on Sersi's molecular rearrangement powers are as yet unrevealed. Sersi is the only living Fifth Level adept at matter transmutation (on a 1-5 scale). She has the ability to alter molecular and atomic structures of all matter including living organisms. However, she has expressed difficulty in rearranging sub-atomic matter.
Sersi has a gifted intellect, and superhuman strength (which she can supplement by psionically levitating heavy objects), stamina, durability, agility, and reflexes. Sersi possesses the ability manipulate cosmic energy to augment her life force, granting her virtual invulnerability and immortality, the ability to project cosmic energy from her eyes or hands in the form of heat, light, or concussive force, and possibly other powers. Sersi is resistant against cold, disease, electricity, energy, heat, radiation, and toxin attacks. She does not age, and can only be killed if her atoms are scattered. Sersi possesses total mental control over her physical form, granting her virtual invulnerability and immortality.