Bond of Agony

As an additional cost to cast this spell, pay X life.
Each other player loses X life.

Harness by Force

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Gain control of any number of target creatures until end of turn. Untap those creatures. They gain haste until end of turn.

Custody Battle

Enchant creature
Enchanted creature has "At the beginning of your upkeep, target opponent gains control of this creature unless you sacrifice a land."

Grimclaw Bats

Flying
{B}, Pay 1 life: Grimclaw Bats gets +1/+1 until end of turn.

Hate Mirage

Choose up to two target creatures you don't control. For each of those creatures, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Tentative Connection

This spell costs {3} less to cast if you control a creature with menace.
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Incite War

Choose one —
• Creatures target player controls attack this turn if able.
• Creatures you control gain first strike until end of turn.
Entwine {2} (Choose both if you pay the entwine cost.)

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Goatnap

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. If that creature is a Goat, it also gets +3/+0 until end of turn.

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.

Death Watch

Enchant creature
When enchanted creature dies, its controller loses life equal to its power and you gain life equal to its toughness.

Bastion of Remembrance

When Bastion of Remembrance enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Wrangle

Gain control of target creature with power 4 or less until end of turn. Untap that creature. It gains haste until end of turn.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Jeering Instigator

Morph {2}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Jeering Instigator is turned face up, if it's your turn, gain control of another target creature until end of turn. Untap that creature. It gains haste until end of turn.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Besmirch

Until end of turn, gain control of target creature and it gains haste. Untap and goad that creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Bloodtracker

Flying
{B}, Pay 2 life: Put a +1/+1 counter on Bloodtracker.
When Bloodtracker leaves the battlefield, draw a card for each +1/+1 counter on it.

Rat Colony

Rat Colony gets +1/+0 for each other Rat you control.
A deck can have any number of cards named Rat Colony.

Captivating Crew

{3}{R}: Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. Activate only as a sorcery.

Fractured Loyalty

Enchant creature
Whenever enchanted creature becomes the target of a spell or ability, that spell or ability's controller gains control of that creature. (This effect lasts indefinitely.)

Font of Agonies

Whenever you pay life, put that many blood counters on Font of Agonies.
{1}{B}, Remove four blood counters from Font of Agonies: Destroy target creature.

Ashnod's Altar

Blood Celebrant

{B}, Pay 1 life: Add one mana of any color.

Garza's Assassin

Sacrifice Garza's Assassin: Destroy target nonblack creature.
Recover—Pay half your life, rounded up. (When another creature is put into your graveyard from the battlefield, you may pay half your life, rounded up. If you do, return this card from your graveyard to your hand. Otherwise, exile this card.)

Swamp

Mountain

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.

Greed

Chainer, Dementia Master

All Nightmares get +1/+1.
{B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types.
When Chainer, Dementia Master leaves the battlefield, exile all Nightmares.

Dying Wish

Enchant creature you control
When enchanted creature dies, target player loses X life and you gain X life, where X is its power.

Traitorous Blood

Gain control of target creature until end of turn. Untap it. It gains trample and haste until end of turn.

Essence Harvest

Target player loses X life and you gain X life, where X is the greatest power among creatures you control.

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Claim the Firstborn

Gain control of target creature with mana value 3 or less until end of turn. Untap that creature. It gains haste until end of turn.

Culling Dais

{T}, Sacrifice a creature: Put a charge counter on Culling Dais.
{1}, Sacrifice Culling Dais: Draw a card for each charge counter on Culling Dais.

Plunge into Darkness

Choose one —
• Sacrifice any number of creatures. You gain 3 life for each creature sacrificed this way.
• Pay any amount of life, then look at that many cards from the top of your library. Put one of those cards into your hand and exile the rest.
Entwine {B} (Choose both if you pay the entwine cost.)

Kari Zev's Expertise

Gain control of target creature or Vehicle until end of turn. Untap it. It gains haste until end of turn.
You may cast a spell with mana value 2 or less from your hand without paying its mana cost.

Grotesque Mutation

Target creature gets +3/+1 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Plague of Vermin

Starting with you, each player may pay any amount of life. Repeat this process until no one pays life. Each player creates a 1/1 black Rat creature token for each 1 life they paid this way.

Traitorous Instinct

Gain control of target creature until end of turn. Untap that creature. Until end of turn, it gets +2/+0 and gains haste.

Hijack

Gain control of target artifact or creature until end of turn. Untap it. It gains haste until end of turn.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Threaten

Untap target creature and gain control of it until end of turn. That creature gains haste until end of turn. (It can attack and {T} this turn.)

Butcher's Glee

Target creature gets +3/+0 and gains lifelink until end of turn. Regenerate it. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Hall of the Bandit Lord

Hall of the Bandit Lord enters tapped.
{T}, Pay 3 life: Add {C}. If that mana is spent on a creature spell, it gains haste.

Dash Hopes

When you cast this spell, any player may pay 5 life. If a player does, counter Dash Hopes.
Counter target spell.

Hatred

As an additional cost to cast this spell, pay X life.
Target creature gets +X/+0 until end of turn.

Greven, Predator Captain

Menace
Greven, Predator Captain gets +X/+0, where X is the amount of life you've lost this turn.
Whenever Greven attacks, you may sacrifice another creature. If you do, you draw cards equal to that creature's power and you lose life equal to that creature's toughness.