Aqua Spirit (DB2-EN006) - Dark Beginning 2 Unlimited

This card cannot be Normal Summoned or Set. This card can only be Special Summoned by removing 1 WATER monster in your Graveyard from play. During each of your opponent's Standby Phases, you can change the battle position of 1 of your opponent's face-up Monster Cards. Once changed, the monster must remain in this position for the rest of the turn.