Gloria Union: Twin Fates in Blue Ocean (2011)

Thousands of years ago, a great kingdom called Euforia flourished making use of a power source known as "Will". Through the centuries, Euforia developed many customs based on the use of Will, but when one day they realized that their civilization would soon come to an end, they poured all their Will into crystals in order to leave a record of their culture behind. After this, Euforia sank to the bottom of the ocean. In the present day, with the ocean now taking up over half of the world, the seas became populated with many pirates. Those pirates, hearing the legend of the crystals, began to search the ocean for clues to their whereabouts. Among those pirates was one young boy dreaming of greatness.