Blasphemous Act

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

Skirk Fire Marshal

Protection from red
Tap five untapped Goblins you control: Skirk Fire Marshal deals 10 damage to each creature and each player.

Calming Verse

Destroy all enchantments you don't control. Then if you control an untapped land, destroy all enchantments you control.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Contagion Engine

When Contagion Engine enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Tumble

Tumble deals 6 damage to each creature with flying.

Rough

Rough deals 2 damage to each creature without flying.

Rough // Tumble

Finale of Eternity

Destroy up to three target creatures with toughness X or less. If X is 10 or more, return all creature cards from your graveyard to the battlefield.

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle Decree of Pain, all creatures get -2/-2 until end of turn.

Soulfire Eruption

Choose any number of target creatures, planeswalkers, and/or players. For each of them, exile the top card of your library, then Soulfire Eruption deals damage equal to that card's mana value to that permanent or player. You may play the exiled cards until the end of your next turn.

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.

Last Laugh

Whenever a permanent other than Last Laugh is put into a graveyard from the battlefield, Last Laugh deals 1 damage to each creature and each player.
When no creatures are on the battlefield, sacrifice Last Laugh.

Delete

Delete deals X damage to each nonartifact creature and each player.

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.")

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Their Name Is Death

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Delayed Blast Fireball

Delayed Blast Fireball deals 2 damage to each opponent and each creature they control. If this spell was cast from exile, it deals 5 damage to each opponent and each creature they control instead.
Foretell {4}{R}{R} (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.)

Wrath of God

Destroy all creatures. They can't be regenerated.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

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.

Toxic Deluge

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

Archfiend of Sorrows

Flying
When Archfiend of Sorrows enters, creatures your opponents control get -2/-2 until end of turn.
Unearth {3}{B}{B} ({3}{B}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Deadly Tempest

Destroy all creatures. Each player loses life equal to the number of creatures they controlled that were destroyed this way.

Akroma's Vengeance

Destroy all artifacts, creatures, and enchantments.
Cycling {3} ({3}, Discard this card: Draw a card.)

Damnation

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Mandate of Abaddon

Choose target creature you control. Destroy all creatures with power less than that creature's power.

Phyrexian Scriptures

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Put a +1/+1 counter on up to one target creature. That creature becomes an artifact in addition to its other types.
II — Destroy all nonartifact creatures.
III — Exile all opponents' graveyards.

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Culling Ritual

Destroy each nonland permanent with mana value 2 or less. Add {B} or {G} for each permanent destroyed this way.

Aligned Hedron Network

When Aligned Hedron Network enters, exile all creatures with power 5 or greater until Aligned Hedron Network leaves the battlefield. (Those creatures return under their owners' control.)

Noxious Field

Enchant land
Enchanted land has "{T}: This land deals 1 damage to each creature and each player."

Chandra's Ignition

Target creature you control deals damage equal to its power to each other creature and each opponent.

Spectacular Showdown

Put a double strike counter on target creature, then goad each creature that had a double strike counter put on it this way. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)
Overload {4}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")