Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Dingus Egg

Whenever a land is put into a graveyard from the battlefield, this artifact deals 2 damage to that land's controller.

Befoul

Destroy target land or nonblack creature. It can't be regenerated.

Helldozer

{B}{B}{B}, {T}: Destroy target land. If that land was nonbasic, untap this creature.

Black Vise

As this artifact enters, choose an opponent.
At the beginning of the chosen player's upkeep, this artifact deals X damage to that player, where X is the number of cards in their hand minus 4.