Piercing Blow (BT29-104) - Fearsome Rivals Foil

[Counter Attack] [Limit 1] If your Leader is black : Negate the attack, then choose any number of your opponent’s Battle Cards that add up to a total energy cost of 4 or less and send them to their owner’s Warp.
[Activate Battle] Choose up to 1 of your black Battle Cards with a [Union] skill and it gets +15000 power and [Critical] for the battle.