Eriel was born the only child of Scientists Cora Moon (The original Moon Girl) and Jack Jupiter (the Original Mr. Jupiter).
Eriel was exposed to Epos Rays( Y'Gnog version of Espeschen Radiation) which prematurely triggered her hereditary abilities of Flight, Speed and Invulnerability - the same as her father while also possessing 'Moon' powers like her mother.
The experiment that turned Eriel into a super-being was kept secret from the rest of the members of the Guardian Guild (the children of the original H.I.W.) as well as the Chaos Coalition. Instead Cora and Jack strove to provide Eriel with as normal a childhood as they could.
Cora's mother, however, a Para-Psychic foresaw the importance of training her granddaughter to hone her special abilities to prepare for her eventual battles with Zackery Turner (Kid Cronos).