Barter in Blood

Doomskar

Destroy all creatures.
Foretell {1}{W}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Damnation

Destroy all creatures. They can't be regenerated.

Spreading Plague

Whenever a creature enters, destroy all other creatures that share a color with it. They can't be regenerated.

Call to the Grave

At the beginning of each player's upkeep, that player sacrifices a non-Zombie creature.
At the beginning of the end step, if no creatures are on the battlefield, sacrifice Call to the Grave.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

End Hostilities

Destroy all creatures and all permanents attached to creatures.

No Mercy

Whenever a creature deals damage to you, destroy it.

Visara the Dreadful

Flying
{T}: Destroy target creature. It can't be regenerated.

Innocent Blood

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature.

Lethal Vapors

Whenever a creature enters, destroy it.
{0}: Destroy Lethal Vapors. You skip your next turn. Any player may activate this ability.

Avatar of Woe

If there are ten or more creature cards total in all graveyards, this spell costs {6} less to cast.
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{T}: Destroy target creature. It can't be regenerated.