Another Crab's Treasure

This is the final story boss of The Old Ocean area. It is fought in the At Whorl's End area. The first phase of this fight is a normal battle; howver, Praya Dubia's second phase doesn't allow you to damage it, but requires you to just keep dodging its onslaught while its health slowly drains. For an easy fight, turn on the assist mode that gives Kril a gun to easily one shot the boss, during the first phase.