Lethal Vapors

Whenever a creature enters, destroy it.
{0}: Destroy Lethal Vapors. You skip your next turn. Any player may activate this ability.

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Havoc Demon

Flying
When Havoc Demon dies, all creatures get -5/-5 until end of turn.

Stitch Together

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

Swamp

Prickly Boggart

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Balthor the Defiled

Minion creatures get +1/+1.
{B}{B}{B}, Exile Balthor the Defiled: Each player returns all black and all red creature cards from their graveyard to the battlefield.

Unburden

Target player discards two cards.
Cycling {2} ({2}, Discard this card: Draw a card.)

Fists of the Demigod

Enchant creature
As long as enchanted creature is black, it gets +1/+1 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
As long as enchanted creature is red, it gets +1/+1 and has first strike.

Kulrath Knight

Flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)
Creatures your opponents control with counters on them can't attack or block.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Contaminated Bond

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Whenever enchanted creature attacks or blocks, its controller loses 3 life.

Smolder Initiate

Whenever a player casts a black spell, you may pay {1}. If you do, target player loses 1 life.

Soul Reap

Destroy target nongreen creature. Its controller loses 3 life if you've cast another black spell this turn.

Caustic Tar

Enchant land
Enchanted land has "{T}: Target player loses 3 life."

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Morbid Hunger

Morbid Hunger deals 3 damage to any target. You gain 3 life.
Flashback {7}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Innocent Blood

Each player sacrifices a creature of their choice.

Pulling Teeth

Clash with an opponent. If you win, target player discards two cards. Otherwise, that player discards a card. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Extractor Demon

Flying
Whenever another creature leaves the battlefield, you may have target player mill two cards.
Unearth {2}{B} ({2}{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.)

Disturbing Plot

Return target creature card from a graveyard to its owner's hand.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)

Ghastly Demise

Destroy target nonblack creature if its toughness is less than or equal to the number of cards in your graveyard.

Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

Cry of Contrition

Target player discards a card.
Haunt (When this spell card is put into a graveyard after resolving, exile it haunting target creature.)
When the creature Cry of Contrition haunts dies, target player discards a card.

Koskun Falls

At the beginning of your upkeep, sacrifice Koskun Falls unless you tap an untapped creature you control.
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Shade's Form

Enchant creature
Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."
When enchanted creature dies, return that card to the battlefield under your control.

Lingering Death

Enchant creature
At the beginning of the end step of enchanted creature's controller, that player sacrifices that creature.

Promise of Power

Choose one —
• You draw five cards and you lose 5 life.
• Create an X/X black Demon creature token with flying, where X is the number of cards in your hand.
Entwine {4} (Choose both if you pay the entwine cost.)

Morsel Theft

Prowl {1}{B} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.)
Target player loses 3 life and you gain 3 life. If this spell's prowl cost was paid, draw a card.