William Urbesh is the heir of the Urbesh clan in Violent Mountain Sector. He was a cowardly and incompetent pilot. The Rim Guardians entrusted William to Ves Larkinson, and tasked him with turning William into an expert candidate.
William was trained by the Larkinsons, and proved too weak willed and cowardly. As standard training did not work, Ves Larkinson decided to remove William's fear through spiritual means. He mixed his spirit with a fragment of Nyxie, a powerful alien tyrant. After the spiritual surgery, William became mute and rather abnormal, but he also became a competent pilot.
It was later found by Ves that the new Silent William was incapable of turning into an expert candidate. This is because the original William and Nyxie were warring a battle in his mind, and one needs a focused mentality to become an expert. Ves solved this by smashing William's spirit apart, killing him, and then rebuilding him, like he does with his spiritual products. The resulting William is an expert candidate. During this second spiritual surgery, Cassandra Breyer interfered, although the results of her meddling are unclear.