Malevolent Whispers

Gain control of target creature until end of turn. Untap that creature. It gets +2/+0 and gains haste until end of turn.
Madness {3}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Rakdos Guildgate

This land enters tapped.
{T}: Add {B} or {R}.

Greven, Predator Captain

Menace
Greven 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.

Rakdos Riteknife

Equipped creature gets +1/+0 for each blood counter on this Equipment and has "{T}, Sacrifice a creature: Put a blood counter on Rakdos Riteknife."
{B}{R}, Sacrifice this Equipment: Target player sacrifices a permanent of their choice for each blood counter on this Equipment.
Equip {2}

Vulturous Aven

Flying
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, you draw two cards and you lose 2 life.

Fell Stinger

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, target player draws two cards and loses 2 life.

Quest for the Gravelord

Whenever a creature dies, you may put a quest counter on this enchantment.
Remove three quest counters from this enchantment and sacrifice it: Create a 5/5 black Zombie Giant creature token.

Rakshasa Gravecaller

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, create two 2/2 black Zombie creature tokens.

Rakdos Cluestone

{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice this artifact: Draw a card.

Portent of Betrayal

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Traitorous Blood

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

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

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.

Rescue from the Underworld

As an additional cost to cast this spell, sacrifice a creature.
Choose target creature card in your graveyard. Return that card and the sacrificed card to the battlefield under your control at the beginning of your next upkeep. Exile Rescue from the Underworld.

Disciple of Griselbrand

{1}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Press into Service

Support 2. (Put a +1/+1 counter on each of up to two target creatures.)
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

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.

Lose Calm

Gain control of target creature until end of turn. Untap that creature. It gains haste and menace until end of turn. (A creature with menace can't be blocked except by two or more creatures.)

Torrent of Souls

Return up to one target creature card from your graveyard to the battlefield if {B} was spent to cast this spell. Creatures target player controls get +2/+0 and gain haste until end of turn if {R} was spent to cast this spell. (Do both if {B}{R} was spent.)

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Ashnod's Altar

Minion's Return

Flash
Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

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.

Swamp

Tormented Thoughts

As an additional cost to cast this spell, sacrifice a creature.
Target player discards a number of cards equal to the sacrificed creature's power.

Rakdos Keyrune

{T}: Add {B} or {R}.
{B}{R}: This artifact becomes a 3/1 black and red Devil artifact creature with first strike until end of turn.

Kheru Bloodsucker

Whenever a creature you control with toughness 4 or greater dies, each opponent loses 2 life and you gain 2 life.
{2}{B}, Sacrifice another creature: Put a +1/+1 counter on this creature.

Weaponize the Monsters

{2}, Sacrifice a creature: This enchantment deals 2 damage to any target.

Hijack

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

Charmbreaker Devils

At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, this creature gets +4/+0 until end of turn.

Blood Aspirant

Whenever you sacrifice a permanent, put a +1/+1 counter on this creature.
{1}{R}, {T}, Sacrifice a creature or enchantment: This creature deals 1 damage to target creature. That creature can't block this turn.

Mountain

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.

Act of Aggression

({R/P} can be paid with either {R} or 2 life.)
Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Furnace Celebration

Whenever you sacrifice another permanent, you may pay {2}. If you do, this enchantment deals 2 damage to any target.

Rage Thrower

Whenever another creature dies, this creature deals 2 damage to target player or planeswalker.

Bond of Passion

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Bond of Passion deals 2 damage to any other target.

Minister of Pain

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, creatures your opponents control get -1/-1 until end of turn.

Consuming Vapors

Target player sacrifices a creature of their choice. You gain life equal to that creature's toughness.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Terramorphic Expanse

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Butcher of Malakir

Flying
Whenever this creature or another creature you control dies, each opponent sacrifices a creature of their choice.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Blackcleave Cliffs

This land enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.

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.)

Sidisi, Undead Vizier

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When Sidisi exploits a creature, you may search your library for a card, put it into your hand, then shuffle.

Altar's Reap

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

Spawning Pit

Sacrifice a creature: Put a charge counter on this artifact.
{1}, Remove two charge counters from this artifact: Create a 2/2 colorless Spawn artifact creature token.

Silumgar Butcher

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, target creature gets -3/-3 until end of turn.

Undercity Informer

{1}, Sacrifice a creature: Target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Infernal Plunge

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

Mindleech Ghoul

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, each opponent exiles a card from their hand.

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature you control enters, if you didn't cast it from your hand, it gains haste until your next turn.

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.

Qarsi Sadist

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, target opponent loses 2 life and you gain 2 life.

Juri, Master of the Revue

Whenever you sacrifice a permanent, put a +1/+1 counter on Juri.
When Juri dies, it deals damage equal to its power to any target.

Evolving Wilds

Rot-Tide Gargantua

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, each opponent sacrifices a creature of their choice.

Unbreakable Bond

Return target creature card from your graveyard to the battlefield with a lifelink counter on it.

Mark of Mutiny

Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn. (It can attack and {T} this turn.)

Lyzolda, the Blood Witch

{2}, Sacrifice a creature: Lyzolda deals 2 damage to any target if the sacrificed creature was red. Draw a card if the sacrificed creature was black.

Limits of Solidarity

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Bastion of Remembrance

When this enchantment 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.

Beacon of Unrest

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

Rakdos Locket

{T}: Add {B} or {R}.
{B/R}{B/R}{B/R}{B/R}, {T}, Sacrifice this artifact: Draw two cards.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Tymaret, the Murder King

{1}{R}, Sacrifice another creature: Tymaret deals 2 damage to target player or planeswalker.
{1}{B}, Sacrifice a creature: Return this card from your graveyard to your hand.