[When Digivolving] You may trash 1 card with [Dex], or [DeathX] in its name or with [X Antibody] in its traits in your hand to gain 1 memory. [When Digivolving] If this Digimon has [DoruGreymon] in its digivolution cards, or is digivolving from the trash, delete 1 of your opponent's level 4 of lower Digimon.