Sinkhole

As an additional cost to cast this spell, sacrifice a green creature. Search your library for a green creature card, put it onto the battlefield, then shuffle.

Trample When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

This land enters tapped. 1, T: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Return this land to its owner's hand at the beginning of the next cleanup step.

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

U: Untap this creature. U: This creature gains flying until end of turn. U: This creature gains shroud until end of turn. (It can't be the target of spells or abilities.) 1: This creature gets +1/-1 until end of turn. 1: This creature gets -1/+1 until end of turn.

Each player discards their hand, then draws seven cards.

T: Add C. T, Sacrifice this land: Destroy target nonbasic land.