[AUTO](RC):When this unit attacks a vanguard, if you have an <Aqua Force> vanguard, and if it is the first battle of that turn, this unit gets [Power] +2000 until end of that battle, and at the beginning of the close step of that battle, choose another of your <Aqua Force> rear-guard in the same column as this unit, and exchange positions with this unit. (The state of the card does not change.)