Avatar of Discord

({B/R} can be paid with either {B} or {R}.)
Flying
When Avatar of Discord enters, sacrifice it unless you discard two cards.

Decimate

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

Dreadful Apathy

Enchant creature
Enchanted creature can't attack or block.
{2}{W}: Exile enchanted creature.

Deny the Divine

Counter target creature or enchantment spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Contagion

You may pay 1 life and exile a black card from your hand rather than pay this spell's mana cost.
Distribute two -2/-1 counters among one or two target creatures.

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Eradicator Valkyrie

Flying, lifelink, hexproof from planeswalkers
Boast — {1}{B}, Sacrifice a creature: Each opponent sacrifices a creature or planeswalker. (Activate only if this creature attacked this turn and only once each turn.)

In Search of Greatness

At the beginning of your upkeep, you may cast a permanent spell from your hand with mana value equal to 1 plus the highest mana value among other permanents you control without paying its mana cost. If you don't, scry 1.

Invoke Despair

Target opponent sacrifices a creature of their choice. If they can't, they lose 2 life and you draw a card. Then repeat this process for an enchantment and a planeswalker.

Siren Reaver

Raid — This spell costs {1} less to cast if you attacked this turn.
Flying

Drag to the Underworld

This spell costs {X} less to cast, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Destroy target creature.

Calamity Bearer

If a Giant source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Devastate

Destroy target land. Devastate deals 1 damage to each creature and each player.

Dream Trawler

Flying, lifelink
Whenever you draw a card, Dream Trawler gets +1/+0 until end of turn.
Whenever Dream Trawler attacks, draw a card.
Discard a card: Dream Trawler gains hexproof until end of turn. Tap it.

Bite of the Black Rose

Will of the council — Starting with you, each player votes for sickness or psychosis. If sickness gets more votes, creatures your opponents control get -2/-2 until end of turn. If psychosis gets more votes or the vote is tied, each opponent discards two cards.

Adventurous Impulse

Look at the top three cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Agonizing Remorse

Target opponent reveals their hand. You choose a nonland card from it or a card from their graveyard. Exile that card. You lose 1 life.

Necravolver

Kicker {1}{G} and/or {W} (You may pay an additional {1}{G} and/or {W} as you cast this spell.)
If Necravolver was kicked with its {1}{G} kicker, it enters with two +1/+1 counters on it and with trample.
If Necravolver was kicked with its {W} kicker, it enters with a +1/+1 counter on it and with "Whenever Necravolver deals damage, you gain that much life."

Demon Bolt

Demon Bolt deals 4 damage to target creature or planeswalker.
Foretell {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.)

Infernal Pet

Whenever you cast your second spell each turn, put a +1/+1 counter on Infernal Pet and it gains flying until end of turn.

Blood on the Snow

Choose one —
• Destroy all creatures.
• Destroy all planeswalkers.
Then return a creature or planeswalker card with mana value X or less from your graveyard to the battlefield, where X is the amount of {S} spent to cast this spell. ({S} is mana from a snow source.)

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Blood Clock

At the beginning of each player's upkeep, that player returns a permanent they control to its owner's hand unless they pay 2 life.

Clash of Titans

Target creature fights another target creature. (Each deals damage equal to its power to the other.)

Into the Fire

Choose one —
• Into the Fire deals 2 damage to each creature, planeswalker, and battle.
• Put any number of cards from your hand on the bottom of your library, then draw that many cards plus one.

Skull Raid

Target opponent discards two cards. If fewer than two cards were discarded this way, you draw cards equal to the difference.
Foretell {1}{B} (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.)

Merciless Repurposing

Exile target creature. Incubate 3. (Create an Incubator token with three +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

Grimdancer

Grimdancer enters with your choice of two different counters on it from among menace, deathtouch, and lifelink.

Vengeful Reaper

Flying, deathtouch, haste
Foretell {1}{B} (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.)

Allure of the Unknown

Reveal the top six cards of your library. An opponent exiles a nonland card from among them, then you put the rest into your hand. That opponent may cast the exiled card without paying its mana cost.

Slitherwisp

Flash
Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life.

Mutual Destruction

This spell has flash as long as you control a permanent with flash.
As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Wolf Strike

Target creature you control gets +2/+0 until end of turn if it's night. Then it deals damage equal to its power to target creature you don't control.

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice Underworld Breach.

The Brute

Enchant creature
Enchanted creature gets +1/+0.
{R}{R}{R}: Regenerate enchanted creature.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Impending Doom

Enchant creature
Enchanted creature gets +3/+3 and attacks each combat if able.
When enchanted creature dies, Impending Doom deals 3 damage to that creature's controller.

Burnt Offering

As an additional cost to cast this spell, sacrifice a creature.
Add X mana in any combination of {B} and/or {R}, where X is the sacrificed creature's mana value.

Devourer of Memory

Whenever one or more cards are put into your graveyard from your library, Devourer of Memory gets +1/+1 until end of turn and can't be blocked this turn.
{1}{U}{B}: Mill a card.

Child of Alara

Trample
When Child of Alara dies, destroy all nonland permanents. They can't be regenerated.