The Red Terror

Advanced Species — Whenever a red source you control deals damage to one or more permanents and/or players, put a +1/+1 counter on The Red Terror.

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Judith, Carnage Connoisseur

Whenever you cast an instant or sorcery spell, choose one —
• That spell gains deathtouch and lifelink.
• Create a 2/2 red Imp creature token with "When this creature dies, it deals 2 damage to each opponent."

Bedevil

Destroy target artifact, creature, or planeswalker.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Feed the Swarm

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

Terminate

Destroy target creature. It can't be regenerated.

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Gev, Scaled Scorch

Ward—Pay 2 life.
Other creatures you control enter with an additional +1/+1 counter on them for each opponent who lost life this turn.
Whenever you cast a Lizard spell, Gev, Scaled Scorch deals 1 damage to target opponent.

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature of their choice.

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

War Elemental

When War Elemental enters, sacrifice it unless an opponent was dealt damage this turn.
Whenever an opponent is dealt damage, put that many +1/+1 counters on War Elemental.

Rakdos, the Muscle

Flying, trample
Whenever you sacrifice another creature, exile cards equal to its mana value from the top of target player's library. Until your next end step, you may play those cards, and mana of any type can be spent to cast those spells.
Sacrifice another creature: Rakdos, the Muscle gains indestructible until end of turn. Tap it. Activate only once each turn.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Fire Covenant

As an additional cost to cast this spell, pay X life.
Fire Covenant deals X damage divided as you choose among any number of target creatures.

Ophiomancer

At the beginning of each upkeep, if you control no Snakes, create a 1/1 black Snake creature token with deathtouch.

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.

Blazing Volley

Blazing Volley deals 1 damage to each creature your opponents control.

Exterminator Magmarch

Whenever you cast an instant or sorcery spell that targets only a single nonland permanent an opponent controls, if another opponent controls one or more nonland permanents that spell could target, choose one of those permanents. Copy that spell. The copy targets the chosen permanent.
{1}{B}: Regenerate Exterminator Magmarch.

Maha, Its Feathers Night

Flying, trample
Ward—Discard a card.
Creatures your opponents control have base toughness 1.

Tor Wauki the Younger

Reach, lifelink
If another source you control would deal noncombat damage to a permanent or player, it deals that much damage plus 1 to that permanent or player instead.
Whenever you cast an instant or sorcery spell, Tor Wauki the Younger deals 2 damage to any target.

Overseer of the Damned

Flying
When Overseer of the Damned enters, you may destroy target creature.
Whenever a nontoken creature an opponent controls dies, create a tapped 2/2 black Zombie creature token.

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.")

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Vashta Nerada

Indestructible
Shadow (This creature can block or be blocked by only creatures with shadow.)
Morbid — At the beginning of each end step, if a creature died this turn, put a +1/+1 counter on Vashta Nerada.

Rakdos Signet

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Rakdos, Patron of Chaos

Flying, trample
At the beginning of your end step, target opponent may sacrifice two nonland, nontoken permanents of their choice. If they don't, you draw two cards.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Abrade

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

Insatiable Avarice

Spree (Choose one or more additional costs.)
+ {2} — Search your library for a card, then shuffle and put that card on top.
+ {B}{B} — Target player draws three cards and loses 3 life.

Pestilent Spirit

Menace, deathtouch
Instant and sorcery spells you control have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)