Zosimos works at the Royal Observatory in Inferia City and is a highly respected man because of his work there. The heroes approach him to warn of the Grand Fall, a notion that gets them arrested and sentenced to death for blasphemy, as the Grand Fall is seen as the will of Seyfert. However, Zosimos reads Keele Zeibel's report and decides to measure the distance between the worlds of Inferia and Celestia himself, discovering in fact that the distance has diminished. He rescues the heroes from execution by presenting his finding to the royal family, proof that he is respected in his field. Zosimos is the first person to have measured the distance between the worlds, which was 30 Kalanges at the time. Later in the story, he is part of the negotiations between Inferia and Celestia, and works together with Galenos to form a tactic for the war against Shizel.