Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Structural Assault

Destroy all artifacts, then Structural Assault deals damage to each creature equal to the number of artifacts that were put into graveyards from the battlefield this turn.

Scour from Existence

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Reverent Silence

If you control a Forest, rather than pay this spell's mana cost, you may have each other player gain 6 life.
Destroy all enchantments.

Tranquil Domain

Star of Extinction

Destroy target land. Star of Extinction deals 20 damage to each creature and each planeswalker.

Shatterstorm

Destroy all artifacts. They can't be regenerated.

Burn Away

Burn Away deals 6 damage to target creature. When that creature dies this turn, exile its controller's graveyard.