Number 104: Masquerade (JOTL-EN055)

3 level 4 monsters // During either player's Battle Phase, when an opponent's monster effect is activated: You can detach 1 Xyz Material from this card; negate the activation, and if you do, inflict 800 damage to your opponent. Once per turn: You can send the top card of your opponent's Deck to the Graveyard.