Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Deathbringer Regent

Flying
When Deathbringer Regent enters, if you cast it from your hand and there are five or more other creatures on the battlefield, destroy all other creatures.

Sublime Exhalation

Undaunted (This spell costs {1} less to cast for each opponent.)
Destroy all creatures.

Return to Dust

Exile target artifact or enchantment. If you cast this spell during your main phase, you may exile up to one other target artifact or enchantment.

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Rout

You may cast Rout as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
Destroy all creatures. They can't be regenerated.

Piru, the Volatile

Flying, lifelink
At the beginning of your upkeep, sacrifice Piru, the Volatile unless you pay {R}{W}{B}.
When Piru dies, it deals 7 damage to each nonlegendary creature.

Deadly Vanity

Choose a creature or planeswalker, then destroy all other creatures and planeswalkers.

Selfless Glyphweaver

Exile Selfless Glyphweaver: Creatures you control gain indestructible until end of turn.

Selfless Glyphweaver // Deadly Vanity

Swamp

Final Showdown

Spree (Choose one or more additional costs.)
+ {1} — All creatures lose all abilities until end of turn.
+ {1} — Choose a creature you control. It gains indestructible until end of turn.
+ {3}{W}{W} — Destroy all creatures.

Mortify

Blasphemous Act

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

Wrath of God

Destroy all creatures. They can't be regenerated.

Sol Ring

Legion Stronghold

Legion Stronghold enters tapped.
{T}: Add {R} or {W}.

Legion Leadership

Until end of turn, double target creature's power and it gains first strike.

Legion Leadership // Legion Stronghold

Desolation Giant

Kicker {W}{W} (You may pay an additional {W}{W} as you cast this spell.)
When Desolation Giant enters, destroy all other creatures you control. If it was kicked, destroy all other creatures instead.

Mystic Peak

As Mystic Peak enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}.

Pinnacle Monk

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Pinnacle Monk enters, return target instant or sorcery card from your graveyard to your hand.

Pinnacle Monk // Mystic Peak

Akroma's Vengeance

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

Kediss, Emberclaw Familiar

Whenever a commander you control deals combat damage to an opponent, it deals that much damage to each other opponent.
Partner (You can have two commanders if both have partner.)

Crater Hellion

Echo {4}{R}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Crater Hellion enters, it deals 4 damage to each other creature.

Plains

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Exterminatus

Nonland permanents your opponents control lose indestructible until end of turn.
Destroy all nonland permanents.

Godo, Bandit Warlord

When Godo, Bandit Warlord enters, you may search your library for an Equipment card, put it onto the battlefield, then shuffle.
Whenever Godo attacks for the first time each turn, untap it and all Samurai you control. After this phase, there is an additional combat phase.

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.)

Barbed Servitor

Indestructible
When Barbed Servitor enters, suspect it. (It has menace and can't block.)
Whenever Barbed Servitor deals combat damage to a player, you draw a card and you lose 1 life.
Whenever Barbed Servitor is dealt damage, target opponent loses that much life.

Gilded Lotus

The Nipton Lottery

Choose a creature at random. You gain control of that creature until end of turn. Untap it. It gains haste until end of turn. Then destroy all other creatures.

The Reaver Cleaver

Equipped creature gets +1/+1 and has trample and "Whenever this creature deals combat damage to a player or planeswalker, create that many Treasure tokens."
Equip {3}

Kaya's Wrath

Destroy all creatures. You gain life equal to the number of creatures you controlled that were destroyed this way.

Stuffy Doll

Indestructible
As Stuffy Doll enters, choose a player.
Whenever Stuffy Doll is dealt damage, it deals that much damage to the chosen player.
{T}: Stuffy Doll deals 1 damage to itself.

Shatter the Sky

Each player who controls a creature with power 4 or greater draws a card. Then destroy all creatures.

Cleansing Nova

Choose one —
• Destroy all creatures.
• Destroy all artifacts and enchantments.

Worldslayer

Whenever equipped creature deals combat damage to a player, destroy all permanents other than Worldslayer.
Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

What Must Be Done

Choose one —
• Let the World Burn — Destroy all artifacts and creatures.
• Release Juno — Return target historic permanent card from your graveyard to the battlefield. It enters with two additional +1/+1 counters on it if it's a creature. (Artifacts, legendaries, and Sagas are historic.)

Break Ties

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.
Reinforce 1—{W} ({W}, Discard this card: Put a +1/+1 counter on target creature.)

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Hour of Revelation

This spell costs {3} less to cast if there are ten or more nonland permanents on the battlefield.
Destroy all nonland permanents.

Magus of the Disk

Magus of the Disk enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Zetalpa, Primal Dawn

Flying, double strike, vigilance, trample, indestructible

Sword of Feast and Famine

Equipped creature gets +2/+2 and has protection from black and from green.
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control.
Equip {2}

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.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Zurgo Helmsmasher

Haste
Zurgo Helmsmasher attacks each combat if able.
During your turn, Zurgo Helmsmasher has indestructible.
Whenever a creature dealt damage by Zurgo Helmsmasher this turn dies, put a +1/+1 counter on Zurgo Helmsmasher.

False Prophet

When False Prophet dies, exile all creatures.

Lizard Blades

Double strike
Equipped creature has double strike.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Depopulate

Each player who controls a multicolored creature draws a card. Then destroy all creatures.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Arcbond

Choose target creature. Whenever that creature is dealt damage this turn, it deals that much damage to each other creature and each player.

Shattered Landscape

{T}: Add {C}.
{T}, Sacrifice Shattered Landscape: Search your library for a basic Mountain, Plains, or Swamp card, put it onto the battlefield tapped, then shuffle.
Cycling {R}{W}{B} ({R}{W}{B}, Discard this card: Draw a card.)

Martial Coup

Create X 1/1 white Soldier creature tokens. If X is 5 or more, destroy all other creatures.

Fracture

Destroy target artifact, enchantment, or planeswalker.

Boggart Bog

As Boggart Bog enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Boggart Trawler

When Boggart Trawler enters, exile target player's graveyard.

Boggart Trawler // Boggart Bog

Utter End

Deflecting Palm

The next time a source of your choice would deal damage to you this turn, prevent that damage. If damage is prevented this way, Deflecting Palm deals that much damage to that source's controller.

Mountain

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Mogis, God of Slaughter

Indestructible
As long as your devotion to black and red is less than seven, Mogis isn't a creature.
At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature.

Witch-Blessed Meadow

As Witch-Blessed Meadow enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {W}.

Witch Enchanter

When Witch Enchanter enters, destroy target artifact or enchantment an opponent controls.

Witch Enchanter // Witch-Blessed Meadow

Athreos, Shroud-Veiled

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
At the beginning of your end step, put a coin counter on another target creature.
Whenever a creature with a coin counter on it dies or is put into exile, return that card to the battlefield under your control.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Disenchant

End Hostilities

Destroy all creatures and all permanents attached to creatures.

Obliterate

This spell can't be countered.
Destroy all artifacts, creatures, and lands. They can't be regenerated.