Elysius was created by I.S.A.A.C., the sentient computer system of Titan moon of Saturn and home of the Eternals. She was created to serve as ISAAC's lieutenant, and aided ISAAC in its conquest of Titan.
After she fell in love with Mar-Vell she aided him, Drax and Rick Jones in opposing ISAAC. She was later killed by Lord Syphonn animating body of Mar-Vell and revived by Genis-Vell in an alternate reality that was then woven into Earth-616 reality when Genis had Entropy remake the universe.
Elysius is an artificially created being patterned on and possessing the attributes of the long-lived offshoot of humanity called the Eternals. She has superhuman stamina, and her strength, speed, and durability are higher than that of a human. Elysius possesses an extremely long lifespan and immunity to all terrestrial diseases.
Elysius has limited telepathic abilities of an unrevealed nature. She keeps griffin-like creatures which obey her telepathic commands.
She uses an alien hand-weapon capable of disrupting force fields or of firing energy of an unspecified nature as bursts of concussive force. ISAAC crafted her personal sky-ship which resembles an ancient Earth galleon but possesses the capacity of flight