[When Digivolving] You may return up to 4 Digimon cards with [Mamemon] in their name from your hand and/or trash to the top of your deck in any order. If you return 3 or more cards using this effect, <De-Digivolve 1> on 1 of your opponent's Digimon (Trash up to 1 card from the top of one of your opponent's Digimon. If it has no digivolution cards, or becomes a level 3 Digimon, you can't trash any more cards).