Arria is a priestess of the capital city but does not support the killing of Leymon. She instead joins the group to prevent what the other priests are practicing. During the events of the story, Arria is revealed to be giving information to Albert Mueller, the Captain of the Black Knights. She was once close friends with Albert when they were children growing up in Adelhabith, and the reason Arria originally joined the group was to spy on them. However, she begins to believe that working for Albert is the wrong thing to do, so she warns the group of a planned attack by the Black Knights at the desert town of Laurus. In a difficult moment, she is forced to fight and kill Albert, her childhood love, but at the end of the story, she joins Tilkis Barone in his home country to help eliminate the remaining Spots there.