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.)

Abyssal Gatekeeper

When Abyssal Gatekeeper dies, each player sacrifices a creature of their choice.

Festering Newt

When Festering Newt dies, target creature an opponent controls gets -1/-1 until end of turn. That creature gets -4/-4 instead if you control a creature named Bogbrew Witch.

Zulaport Cutthroat

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

Persistent Specimen

{2}{B}: Return Persistent Specimen from your graveyard to the battlefield tapped.

Stinging Study

You draw X cards and you lose X life, where X is the mana value of a commander you own on the battlefield or in the command zone.

Phyrexian Reclamation

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

Plumb the Forbidden

As an additional cost to cast this spell, you may sacrifice one or more creatures. When you do, copy this spell for each creature sacrificed this way.
You draw a card and you lose 1 life.

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.

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.)

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Black Cat

When Black Cat dies, target opponent discards a card at random.

Whisper, Blood Liturgist

{T}, Sacrifice two creatures: Return target creature card from your graveyard to the battlefield.

Cauldron Familiar

When Cauldron Familiar enters, each opponent loses 1 life and you gain 1 life.
Sacrifice a Food: Return Cauldron Familiar from your graveyard to the battlefield.

Bubbling Cauldron

{1}, {T}, Sacrifice a creature: You gain 4 life.
{1}, {T}, Sacrifice a creature named Festering Newt: Each opponent loses 4 life. You gain life equal to the life lost this way.

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Razaketh, the Foulblooded

Flying, trample
Pay 2 life, Sacrifice another creature: Search your library for a card, put that card into your hand, then shuffle.

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Necropotence

Skip your draw step.
Whenever you discard a card, exile that card from your graveyard.
Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Dusk Legion Zealot

When Dusk Legion Zealot enters, you draw a card and you lose 1 life.

Sol Ring

Hell's Caretaker

{T}, Sacrifice a creature: Return target creature card from your graveyard to the battlefield. Activate only during your upkeep.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Volrath's Stronghold

{T}: Add {C}.
{1}{B}, {T}: Put target creature card from your graveyard on top of your library.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature of their choice.

Cadaver Imp

Flying
When Cadaver Imp enters, you may return target creature card from your graveyard to your hand.

Ashnod's Altar

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Witch's Oven

{T}, Sacrifice a creature: Create a Food token. If the sacrificed creature's toughness was 4 or greater, create two Food tokens instead. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Commander's Plate

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander {3}
Equip {5}

Bone Shredder

Flying
Echo {2}{B} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Bone Shredder enters, destroy target nonartifact, nonblack creature.

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.

Mask of Avacyn

Equipped creature gets +1/+2 and has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {3}

Big Game Hunter

When Big Game Hunter enters, destroy target creature with power 4 or greater. It can't be regenerated.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

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.)

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Basal Thrull

Phyrexian Tower

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

Village Rites

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

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Shambling Ghast

When Shambling Ghast dies, choose one —
• Target creature an opponent controls gets -1/-1 until end of turn.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ormendahl, Profane Prince

Westvale Abbey

{T}: Add {C}.
{5}, {T}, Pay 1 life: Create a 1/1 white and black Human Cleric creature token.
{5}, {T}, Sacrifice five creatures: Transform Westvale Abbey, then untap it.

Westvale Abbey // Ormendahl, Profane Prince

Bogbrew Witch

{2}, {T}: Search your library for a card named Festering Newt or Bubbling Cauldron, put it onto the battlefield tapped, then shuffle.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Burglar Rat

When this creature enters, each opponent discards a card.

Apprentice Necromancer

{B}, {T}, Sacrifice Apprentice Necromancer: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.

Attrition

{B}, Sacrifice a creature: Destroy target nonblack creature.

Cabal Coffers

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

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Gate to Phyrexia

Sacrifice a creature: Destroy target artifact. Activate only during your upkeep and only once each turn.

Heap Doll

Sacrifice Heap Doll: Exile target card from a graveyard.

Elderfang Disciple

When Elderfang Disciple enters, each opponent discards a card.

Tormod, the Desecrator

Whenever one or more cards leave your graveyard, create a tapped 2/2 black Zombie creature token.
Partner (You can have two commanders if both have partner.)

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Shirei, Shizo's Caretaker

Whenever a creature with power 1 or less is put into your graveyard from the battlefield, you may return that card to the battlefield at the beginning of the next end step if Shirei, Shizo's Caretaker is still on the battlefield.

Liliana of the Dark Realms

+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
−3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.
−6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Viscera Seer

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

Skullport Merchant

When Skullport Merchant enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
{1}{B}, Sacrifice another creature or a Treasure: Draw a card.

Strip Mine

{T}: Add {C}.
{T}, Sacrifice Strip Mine: Destroy target land.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Feed the Swarm

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

Blight Mound

Attacking Pests you control get +1/+0 and have menace.
Whenever a nontoken creature you control dies, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."

Yarok's Fenlurker

When Yarok's Fenlurker enters, each opponent exiles a card from their hand.
{2}{B}: Yarok's Fenlurker gets +1/+1 until end of turn.

Thoughtpicker Witch

{1}, Sacrifice a creature: Look at the top two cards of target opponent's library, then exile one of them.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Tevesh Szat, Doom of Fools

+2: Create two 0/1 black Thrull creature tokens.
+1: You may sacrifice another creature or planeswalker. If you do, draw two cards, then draw another card if the sacrificed permanent was a commander.
−10: Gain control of all commanders. Put all commanders from the command zone onto the battlefield under your control.
Tevesh Szat, Doom of Fools can be your commander.
Partner

Mindless Automaton

Mindless Automaton enters with two +1/+1 counters on it.
{1}, Discard a card: Put a +1/+1 counter on Mindless Automaton.
Remove two +1/+1 counters from Mindless Automaton: Draw a card.

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Gleaming Barrier

Defender
When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Urborg, Tomb of Yawgmoth

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

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Sling-Gang Lieutenant

When Sling-Gang Lieutenant enters, create two 1/1 red Goblin creature tokens.
Sacrifice a Goblin: Target player loses 1 life and you gain 1 life.

High Market

{T}: Add {C}.
{T}, Sacrifice a creature: You gain 1 life.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Nyx Lotus

Nyx Lotus enters tapped.
{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.)