Yawgmoth, Thran Physician

Protection from Humans
Pay 1 life, Sacrifice another creature: Put a -1/-1 counter on up to one target creature and draw a card.
{B}{B}, Discard a card: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

The Prismatic Piper

If The Prismatic Piper is your commander, choose a color before the game begins. The Prismatic Piper is the chosen color.
Partner (You can have two commanders if both have partner.)

Bankrupt in Blood

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

Urza's Cave

{T}: Add {C}.
{3}, {T}, Sacrifice Urza's Cave: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Hancock, Ghoulish Mayor

Each other creature you control that's a Zombie or Mutant gets +X/+X, where X is the number of counters on Hancock, Ghoulish Mayor.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Priest of Forgotten Gods

{T}, Sacrifice two other creatures: Any number of target players each lose 2 life and sacrifice a creature of their choice. You add {B}{B} and draw a card.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Nether Traitor

Haste
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return Nether Traitor from your graveyard to the battlefield.

Pawn of Ulamog

Whenever Pawn of Ulamog or another nontoken creature you control dies, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Dauthi Cutthroat

Shadow (This creature can block or be blocked by only creatures with shadow.)
{1}{B}, {T}: Destroy target creature with shadow.

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Puppeteer Clique

Flying
When Puppeteer Clique enters, put target creature card from an opponent's graveyard onto the battlefield under your control. It gains haste. At the beginning of your next end step, exile it.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Lesser Masticore

As an additional cost to cast this spell, discard a card.
{4}: Lesser Masticore deals 1 damage to target creature.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Stronghold Rats

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Stronghold Rats deals combat damage to a player, each player discards a card.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Mire in Misery

Each opponent sacrifices a creature or enchantment of their choice.

Warren Soultrader

Pay 1 life, Sacrifice another creature: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Minas Morgul, Dark Fortress

Minas Morgul, Dark Fortress enters tapped.
{T}: Add {B}.
{3}{B}, {T}: Put a shadow counter on target creature. For as long as that creature has a shadow counter on it, it's a Wraith in addition to its other types. (A creature with shadow can block or be blocked by only creatures with shadow.)

Mind Stone

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

Dauthi Mindripper

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Dauthi Mindripper attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Eviscerator's Insight

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.
Flashback {4}{B} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

Culling the Weak

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

Sightless Ghoul

Sightless Ghoul can't block.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Vengeful Vampire

Flying
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Putrid Goblin

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Dauthi Slayer

Shadow (This creature can block or be blocked by only creatures with shadow.)
Dauthi Slayer attacks each combat if able.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Nasty End

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards. If the sacrificed creature was legendary, draw three cards instead.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Village Rites

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

Evernight Shade

{B}: Evernight Shade gets +1/+1 until end of turn.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Wingrattle Scarecrow

Wingrattle Scarecrow has flying as long as you control a blue creature.
Wingrattle Scarecrow has persist as long as you control a black creature. (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Butcher Ghoul

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Vashta Nerada

Indestructible
Shadow (This creature can block or be blocked by only creatures with shadow.)
Morbid — At the beginning of each end step, if a creature died this turn, put a +1/+1 counter on Vashta Nerada.

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Costly Plunder

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

Illuminor Szeras

Secrets of the Soul — {T}, Sacrifice another creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Rain of Filth

Until end of turn, lands you control gain "Sacrifice this land: Add {B}."

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Dauthi Ghoul

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever a creature with shadow dies, put a +1/+1 counter on Dauthi Ghoul.

Maze of Shadows

{T}: Add {C}.
{T}: Untap target attacking creature with shadow. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Geralf's Messenger

Geralf's Messenger enters tapped.
When Geralf's Messenger enters, target opponent loses 2 life.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Ashnod's Altar

Beseech the Mirror

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Search your library for a card, exile it face down, then shuffle. If this spell was bargained, you may cast the exiled card without paying its mana cost if that spell's mana value is 4 or less. Put the exiled card into your hand if it wasn't cast this way.

Imperial Seal

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Victimize

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

Vampiric Tutor

Wishclaw Talisman

This artifact enters with three wish counters on it.
{1}, {T}, Remove a wish counter from this artifact: Search your library for a card, put it into your hand, then shuffle. An opponent gains control of this artifact. Activate only during your turn.

Dockside Chef

{1}{B}, Sacrifice an artifact or creature: Draw a card.

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Dauthi Horror

Shadow (This creature can block or be blocked by only creatures with shadow.)
Dauthi Horror can't be blocked by white creatures.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.