Bane of the Living

Morph {X}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Bane of the Living is turned face up, all creatures get -X/-X until end of turn.

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.

Starstorm

Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)

Baleful Mastery

You may pay {1}{B} rather than pay this spell's mana cost.
If the {1}{B} cost was paid, an opponent draws a card.
Exile target creature or planeswalker.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Blasphemous Act

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

Transmogrifying Wand

Transmogrifying Wand enters with three charge counters on it.
{1}, {T}, Remove a charge counter from Transmogrifying Wand: Destroy target creature. Its controller creates a 2/4 white Ox creature token. Activate only as a sorcery.

Nest of Scarabs

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Oblation

The owner of target nonland permanent shuffles it into their library, then draws two cards.

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Reconstruct History

Return up to one target artifact card, up to one target enchantment card, up to one target instant card, up to one target sorcery card, and up to one target planeswalker card from your graveyard to your hand.
Exile Reconstruct History.

Phyrexian Rebirth

Destroy all creatures, then create an X/X colorless Phyrexian Horror artifact creature token, where X is the number of creatures destroyed this way.

Rolling Thunder

Rolling Thunder deals X damage divided as you choose among any number of targets.

Magmaquake

Magmaquake deals X damage to each creature without flying and each planeswalker.

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

The Great Aurora

Each player shuffles all cards from their hand and all permanents they own into their library, then draws that many cards. Each player may put any number of land cards from their hand onto the battlefield. Exile The Great Aurora.

Introduction to Annihilation

Exile target nonland permanent. Its controller draws a card.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Perilous Vault

{5}, {T}, Exile Perilous Vault: Exile all nonland permanents.

Ichor Explosion

As an additional cost to cast this spell, sacrifice a creature.
All creatures get -X/-X until end of turn, where X is the sacrificed creature's power.

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

Divine Reckoning

Each player chooses a creature they control. Destroy the rest.
Flashback {5}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fumigate

Destroy all creatures. You gain 1 life for each creature destroyed this way.

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Oblivion Stone

{4}, {T}: Put a fate counter on target permanent.
{5}, {T}, Sacrifice Oblivion Stone: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.

Sudden Demise

Choose a color. Sudden Demise deals X damage to each creature of the chosen color.

Slaughter the Strong

Each player chooses any number of creatures they control with total power 4 or less, then sacrifices all other creatures they control.

Nevinyrral's Disk

Nevinyrral's Disk enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

The Battle of Bywater

Destroy all creatures with power 3 or greater. Then create a Food token for each creature you control. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Rampage of the Clans

Destroy all artifacts and enchantments. For each permanent destroyed this way, its controller creates a 3/3 green Centaur creature token.

Ezuri's Predation

For each creature your opponents control, create a 4/4 green Phyrexian Beast creature token. Each of those tokens fights a different one of those creatures.

Tornado Elemental

When Tornado Elemental enters, it deals 6 damage to each creature with flying.
You may have Tornado Elemental assign its combat damage as though it weren't blocked.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.