Vyvnas-Bok was one of the Crystal Souls abducted by the Empire in the Empire-Avernum War. He was held in the dark prison of Angierach where Midori tormented him with a sea of false images in an attempt to break his will and make him a tool of the Empire. He was rescued by the Empire War Heroes and returned to the Vahnatai, but as years passed, the consequences of his torment began to surface, and Vyvnas grew increasingly unstable. He assisted Rentar-Ihrno in her plagues against the Empire and again in her retribution against Avernum. He was killed during the latter conflict, by adventurers.