Leviamon's Abyssal Resurgence

This spell can only be cast if you control a creature with power 7 or greater. Return any number of target creature cards from your graveyard to the battlefield. They become blue, black, and green Digimon creatures in addition to their other colors and types and gain islandwalk. Sacrifice those creatures at the beginning of your next end step unless you pay {2} for each creature you wish to keep on the battlefield.