Destined Aurox is Neferet's vessel, created by the sacrifice of Linda Heffer. He is pretty much just a killing machine at this point, until, at the ritual gone wrong, near the end of the book, he kills Dragon and says "No!” Aurox said. “No.” He looked from the Sword Master’s battered body and his gaze found me. “Zoey! I chose a different future. I did!” (Direct quote) .
He contains Heaths soul, thus meaning that he's not evil. Zoey sees Heath in him at the end of Destined, through her seer stone, as well.
Hidden
A vessel for Darkness created with Linda Heffer's death. Because of the sacrifice's weakness, Nyx is able to insert Heath's soul inside, which almost gives him a form of humanity. Aurox feeds off of Darkness, fear, and other negative feelings, which cause him to turn into a bull. He is extremely powerful, and in Destined, Neferet makes the attempt to pass him off as a gift from Nyx. This fails however, when he kills Dragon and almost kills Rephaim. Although he has no memories of his past life as Heath, he can't help but feel sympathy and care for Zoey. In one example, Aurox offers Zoey a Kleenex when she begins to cry, something Heath would always do for her. His connection to her is shown again when he accidentally said her name when being intimate with another fledgling.