Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Gnawing Vermin

When Gnawing Vermin enters, target player mills two cards.
When Gnawing Vermin dies, target creature you don't control gets -1/-1 until end of turn.

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Spymaster's Vault

Spymaster's Vault enters tapped unless you control a Swamp.
{T}: Add {B}.
{B}, {T}: Target creature you control connives X, where X is the number of creatures that died this turn. (Draw X cards, then discard X cards. Put a +1/+1 counter on that creature for each nonland card discarded this way.)

Bloodline Culling

Choose one —
• Target creature gets -5/-5 until end of turn.
• Creature tokens get -2/-2 until end of turn.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Maha, Its Feathers Night

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

Final Parting

Search your library for two cards. Put one into your hand and the other into your graveyard. Then shuffle.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Slice from the Shadows

This spell can't be countered. (This includes by the ward ability.)
Target creature gets -X/-X until end of turn.

Orcish Bowmasters

Flash
When Orcish Bowmasters enters and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Disfigure

Target creature gets -2/-2 until end of turn.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Blood Pet

Sudden Death

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Target creature gets -4/-4 until end of turn.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Kaervek, the Spiteful

Festering Goblin

When Festering Goblin dies, target creature gets -1/-1 until end of turn.

Dark Salvation

Target player creates X 2/2 black Zombie creature tokens, then up to one target creature gets -1/-1 until end of turn for each Zombie that player controls.

Persist

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

Skirge Familiar

Lobelia Sackville-Baggins

Flash
Menace
When Lobelia Sackville-Baggins enters, exile target creature card from an opponent's graveyard that was put there from the battlefield this turn, then create X Treasure tokens, where X is the exiled card's power.

Skinrender

When Skinrender enters, put three -1/-1 counters on target creature.

Dark Ritual

Feed the Swarm

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

Whisper of the Dross

Target creature gets -1/-1 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Terisiare's Devastation

You lose X life and create X tapped Powerstone tokens. Then all creatures get -1/-1 until end of turn for each artifact you control. (The tokens are artifacts with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Mutilate

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

Terror Tide

Fathomless descent — All creatures get -X/-X until end of turn, where X is the number of permanent cards in your graveyard.

Blightbelly Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Hunted Bonebrute

Menace
When Hunted Bonebrute enters, target opponent creates two 1/1 white Dog creature tokens.
When Hunted Bonebrute dies, each opponent loses 3 life.
Disguise {1}{B}

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

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.)

Curse of Death's Hold

Enchant player
Creatures enchanted player controls get -1/-1.

Stab

Kaervek, the Punisher

Whenever you commit a crime, exile up to one target black card from your graveyard and copy it. You may cast the copy. If you do, you lose 2 life. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime. Copies of permanent spells become tokens.)

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Massacre Girl, Known Killer

Menace
Creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls dies, if its toughness was less than 1, draw a card.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Heraldic Banner

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Nowhere to Run

Flash
When Nowhere to Run enters, target creature an opponent controls gets -3/-3 until end of turn.
Creatures your opponents control can be the targets of spells and abilities as though they didn't have hexproof. Ward abilities of those creatures don't trigger.

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Swamp

Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Grasp of Darkness

Target creature gets -4/-4 until end of turn.

Peat Bog

Peat Bog enters tapped with two depletion counters on it.
{T}, Remove a depletion counter from Peat Bog: Add {B}{B}. If there are no depletion counters on Peat Bog, sacrifice it.

Skithiryx, the Blight Dragon

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{B}: Skithiryx, the Blight Dragon gains haste until end of turn.
{B}{B}: Regenerate Skithiryx.

Glistening Deluge

All creatures get -1/-1 until end of turn. Creatures that are green and/or white get an additional -2/-2 until end of turn.

Night Clubber

When Night Clubber enters, creatures your opponents control get -1/-1 until end of turn.
Blitz {2}{B} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Demonic Stench

Each creature that blocked this turn gets -1/-1 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Hezrou

Whenever one or more creatures you control become blocked, each blocking creature gets -1/-1 until end of turn.

Hezrou // Demonic Stench

Grim Hireling

Whenever one or more creatures you control deal combat damage to a player, create two Treasure tokens.
{B}, Sacrifice X Treasures: Target creature gets -X/-X until end of turn. Activate only as a sorcery.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Harvester of Souls

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another nontoken creature dies, you may draw a card.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Vat Emergence

Put target creature card from a graveyard onto the battlefield under your control. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Liliana, Waker of the Dead

+1: Each player discards a card. Each opponent who can't loses 3 life.
−3: Target creature gets -X/-X until end of turn, where X is the number of cards in your graveyard.
−7: You get an emblem with "At the beginning of combat on your turn, put target creature card from a graveyard onto the battlefield under your control. It gains haste."

Gisa, Glorious Resurrector

If a creature an opponent controls would die, exile it instead.
At the beginning of your upkeep, put all creature cards exiled with Gisa, Glorious Resurrector onto the battlefield under your control. They gain decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Black Sun's Twilight

Up to one target creature gets -X/-X until end of turn. If X is 5 or more, return a creature card with mana value X or less from your graveyard to the battlefield tapped.

Archfiend of Sorrows

Flying
When Archfiend of Sorrows enters, creatures your opponents control get -2/-2 until end of turn.
Unearth {3}{B}{B} ({3}{B}{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.)

Withering Torment

Destroy target creature or enchantment. You lose 2 life.

Gixian Puppeteer

Whenever you draw your second card each turn, each opponent loses 2 life and you gain 2 life.
When Gixian Puppeteer dies, return another target creature card with mana value 3 or less from your graveyard to the battlefield.

Necromancy

You may cast Necromancy as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
When Necromancy enters, if it's on the battlefield, it becomes an Aura with "enchant creature put onto the battlefield with Necromancy." Put target creature card from a graveyard onto the battlefield under your control and attach Necromancy to it. When Necromancy leaves the battlefield, that creature's controller sacrifices it.

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Liliana, the Last Hope

+1: Up to one target creature gets -2/-1 until your next turn.
−2: Mill two cards, then you may return a creature card from your graveyard to your hand.
−7: You get an emblem with "At the beginning of your end step, create X 2/2 black Zombie creature tokens, where X is two plus the number of Zombies you control."