Seiu Ou (汪・青宇 Ō Seiu) are an ancient mamodo team who fights along Ibaris, usually. Their spells are based on Energy. Babiru eyes are never seen; and Seiu is his brainwashed bookkeeper. When first introduced, Babiru was helping a team of ancient mamodo to burn Baransha's book. They're too last seen in the ancient battle, when Brago burns all ancient mamodo books (including his book). Seiu's japanese voice is unknown.