Before they had a divorce, Johnny Cage and Sonya Blade had Cassie and raised her in America. Due to Sonya's obsession in her work and not spending enough time with her family, Johnny had a divorce with Sonya, much to Cassie's sadness. In her youth, Cassie acted somewhat spoiled, but changed after becoming involved in her family's legacy when she was kidnapped by the Black Dragon. Trained by both her parents and now a sergeant, Cassie is a skilled fighter serving in the Special Forces. Cassie leads her own team to protect Earthrealm as she tries to live up to her parents' legacy.
Although Cassie Cage acts confident and is quick witted like Johnny, Cassie suffers from self doubt due to her mother's strict behavior and her father's reputation. Along with this, she doesn't have complete control over her shadow abilities that she inherited from her father. Cassie proves to have a great sense of morals, as she refuses to kill her enemies if it can be avoided. She is childhood friends with Jacqui Briggs, who is also part of the team she leads along with Kung Jin and Takeda Takahashi. Overtime, Cassie becomes a better leader and more self confident with her friends' aid, proving she is just as much of a hero as her own parents.
