Lillith

Lillith spent 16 years in the Lowe Foundation Laboratory before eventually coming into her powers, with those powers came an alternate reality version of herself. She has merged with this alternate version when she uses her powers, but when she is not using them she is herself. She works for Stark Industries. You meet lillith in the gym and watch as she trains as Ruby~her alternate personality~ then switches back to her normal self. (Rubys universe)