When you would use this card, if you have a Digimon with [X Antibody] in its digivolution cards in play, reduce the cost by 2.
[Main] Choose any number of your opponent's Digimon and/or Tamers whose combined play costs are less than or equal to the play cost of 1 of your Digimon with [Greymon] in its name, and delete all of the chosen cards. Then, 1 of your Digimon with [Greymon] in its name may attack a player.