The Order of the Knights (siglum: OOK) is an organization of Elysion. The Knights are divided in classes by the level of their most powerful technique - if it's S-rank the Knights is a 1st class, if it's A-rank the Knights is a 2nd class etc. Main Location: Empire-Kingdom of Mer - Mer Island - Mer Plains - Mer City - OOA Headquarters. Active Members: All the existing Knights (7000+).