William Whele was David Whele's son and the heir of Vega's other powerful ruling family. William is Vega's Principate. Specifically, he's the religious leader of the Church of the Savior, the religion that has grown since the Extermination War all based around the concept of "The Chosen One." Unlike his cunning politician father David, he is kind hearted to his flock. He is also very much in love with Claire Riesen and welcomes their betrothal, even if he admits it is a political move by their fathers. William may also work in legion with Gabriel, since he had informed Gabriel that they had found "The Chosen One," who is Alex Lannon.
It is now known that William is the leader of Black Acolytes in Vega. It is unknown whether or not he survived being in the desert (because of his father), but he is seem in a hallucination by David Whele at the start of season 2. William's father appears to be regretting his decision to leave him in the desert alone.
William later in season 2 returns to the V-1 section of Vega and tries to lie about him being the Chosen One himself. William is later revealed that he actually believes that he's the Chosen One rather pretending to be one. Possibly due to a mental injury, he preaches to the citizens of Vega as if he was sent by God Himself. However, he is later killed by David, his own father, because he began to destroy Vega's chances of surviving an Eight-Ball army.
William originally was a great preacher of Savorism and a humble person. It's later revealed though that he's the determined follower of Gabriel's Black Acolytes. He resents his father for being who he is and he keeps his true self under raps, until Claire Riesen, his wife, figures out who he really is. He is overly emotional at times.