Very little was known about the Defiler when he joined the Legion a short time before the Battle of Yavin. After proving exceptionally proficient during training, he was tasked by 8311 himself to destroy the Imperial star destroyer Bombardment, which he succeeded in doing. During this mission, the Defiler was supervised by Jandek Martel, who began to form an affection for the Defiler. Afterwards, the Defiler was dispatched to assassinate Senator Binks, which he apparently also succeeded in doing, although afterwards it became uncertain whether the person he killed had actually been Binks.