Karolina Dean was born to famous actors Frank and Leslie Dean, who unbeknownst to her were aliens from the planet Majesdane and members of the Pride. After learning of her parents' true intentions, she ran away with the other Pride members' children, in the process learning that her medical alert bracelet was actually a Majesdanian device meant to suppress her powers. She later learned that she had been betrothed to Prince Xavin of the Skrull Empire, in the process admitting to her friends and to Xavin that she was a lesbian. She eventually fell in love with and began dating the superheroine Lightspeed.
Years after the Runaways had disbanded, Karolina began attending college while undergoing therapy sessions to deal with the trauma she'd endured as a Runaway. However, her life was interrupted again when Gert Yorkes was returned to life, and the other Runaways came knocking at her college dorm room's door. While she initially declined their invitation back, she would eventually rejoin the team. Complications with a super-villainess led to her breaking up with Lightspeed, though she ultimately kindled a romantic relationship with her long-time teammate, Nico Minoru.
Karolina Dean is the daughter of Jonah, a Gibborim, and Leslie Dean, a human. After removing her Gibborim bracelet for the first time, Karolina discovered her powers of light generation. Upon reuniting with her childhood friends, they discovered that their parents used PRIDE to cover up ceremonial sacrifices of the church. She teamed up with her friends and formed the Runaways. Having been framed for Destiny Gonzalez's murder, and with no other choice, they are forced to run.