Damnation

Destroy all creatures. They can't be regenerated.

Blasphemous Act

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

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

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 this card, all creatures get -2/-2 until end of turn.

Villainous Wrath

Target opponent loses life equal to the number of creatures they control. Then destroy all creatures.

Toxic Deluge

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

Nevinyrral's Disk

This artifact enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Blood Money

Destroy all creatures. For each nontoken creature destroyed this way, you create a tapped Treasure token.

The Last Ronin

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy all creatures.
II — Mill four cards. When you do, return target creature card from your graveyard to your hand.
III — Whenever a creature you control attacks alone this turn, put three +1/+1 counters on it. It gains trample, lifelink, and indestructible until end of turn.

Slash the Ranks

Destroy all creatures and planeswalkers except for commanders.

Promise of Loyalty

Each player puts a vow counter on a creature they control and sacrifices the rest. Each of those creatures can't attack you or planeswalkers you control for as long as it has a vow counter on it.

Ondu Skyruins

Ondu Inversion

Ondu Inversion // Ondu Skyruins

Overwhelming Forces

Destroy all creatures target opponent controls. Draw a card for each creature destroyed this way.

Blasphemous Edict

You may pay {B} rather than pay this spell's mana cost if there are thirteen or more creatures on the battlefield.
Each player sacrifices thirteen creatures of their choice.

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.

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.