Text: You must be a Villain. You must Drop 1 to use this card's effect from your hand. ATTACK RESPONSE When your Rival or their Mono or Dual Ally attacks [1]: Stop that attack.
FAQs/Rulings
What does "Drop 1" mean?
It means to place 1 card from your hand on the bottom of your Main Deck.
Is this effect mandatory?
No, Crystal costs are optional and must only be paid if you wish to use the effect.