Use when entering Combat. Reveal your hand to your opponent. If at least 3 cards in your hand are Black Style cards attach this card to your Main Personality. While attached, you may discard a card from your hand during your "Attacker Attacks" phase to discard one of your opponent's Non-Combat, Ally, or Battleground cards in play.
Go ahead Majin Buu, clean up this town. Just don't overdo it. We wouldn't want the whole planet to disappear.