At some point in early MC, Quatre discovers that his father had created for him in a test tube a much younger sister named Katherine Oud Winner, who was born to be his "spare"- a clone from whom organs could be harvested in the event of an emergency. Along with Trowa Barton, who is working under the alias 'Doktor T', Quatre has been developing 4 new mobile suits using his family's resources- Snow White, Warlock, Prometheus, and Scheherazade. When his sister Katherine is labeled a rebel for interfering in a battle between rebels and Mars Federation forces, he takes her to his base of operations to train her to pilot one of the suits.