Darth Xera took a young apprentice of his own and renamed the boy Darth Trefitz. They practiced the ways of the dark side in secret, and partially in keeping with the Rule of Two, Trefitz killed Xera. He then went in search of a suitable student. He briefly considered Melany Baclaw, the niece of a late Jedi Knight, but she was not strong enough in the Force. He eventually chose Melany's younger sister, Prille Baclaw. Prille was in a group of young Imperial cadets who were attacked by a mob on Coruscant. Trefitz rescued her and an injured companion; the companion died, but Trefitz was able to heal Prille's less serious wounds instantly. She immediately asked to learn how to do what he did, and she soon became Darth Inferna.