Prime Minister Marius Bassianus is a member of one of three Guild houses purged by Delphine Eraclea who was taken under the protection of the Anatoray royal family. After the death of his daughter Euris, Marius took care of Princess Sophia as if she were his own daughter. He and the Emperor killed each other during the Disith attack on the Anatoray capital after a dispute on Sophia's status as heir to the throne.

He is entrusted with the Mysterion held by his family but surrenders it to Alex Row before his death so that it can be kept safe. His generosity is shown in the desire to grant land to Disith's people after its collapse and when he allows his Guild ship as training ground for the allied assault on Guild forces.