Lexa Pierce has a twin brother named Leo Pierce, who in times of anger, was named Troy. Lexa's parents worked for the military, in a concentration camp, during her youth. Their work involved experiments to find a formula for their mutations. At 14, Lexa and her Twin brother escaped their confinement. After their escape Troy's powers went out of control. Following this, Lexa agreed to work for Eckhart, thinking that they were working on a way to bring his abilities back under control, but it ultimately proved to be a ruse. Lexa later worked for The Dominion, afterwards, she was directed to clear up Adam Kane's mess, she assented to this assignment to obtain information on her brother's location. Eventually Lexa was forced to use her powers to kill her brother to save Brennan Mulwray. She la