Hangyaku-sei Million Arthur

The legendary sword “Excalibur” weighs and measures all. Anyone it deems worthy of gaining tremendous power does so,and inherits the name “Arthur”. However, Excalibur dubs generously. With an overabundance of “worthy” dignitaries, six Arthurs travel to England to defeat the corrupt leadership that plagues their country and the world.

(Source: Funimation)
Based on Square Enix's massively multi-player online role-playing game.