Dio Eraclea is the sixteen-year-old younger brother of the most powerful Guild member, Maestro Delphine Eraclea. People see him as a rare find that will someday take over the Guild. He is very playful and fearless, and treats many things like they were games. His odd nature can be seen in his awe of Claus Valca's skills and giving him the nickname "Immelmann" (referring to the World War I German ace, Max Immelmann and the manoeuvre Claus frequently used while flying, the Immelmann turn). This strange nature is mostly due to the Guild lifestyle and fear of his sister Delphine.