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.)

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Fiend Artisan

This creature gets +1/+1 for each creature card in your graveyard.
{X}{B/G}, {T}, Sacrifice another creature: Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Bojuka Bog

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

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Underrealm Lich

If you would draw a card, instead look at the top three cards of your library, then put one into your hand and the rest into your graveyard.
Pay 4 life: Underrealm Lich gains indestructible until end of turn. Tap it.

Grave Titan

Deathtouch
Whenever Grave Titan enters or attacks, create two 2/2 black Zombie creature tokens.

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.

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker of their choice.

Night's Whisper

Command Tower

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

Malakir Mire

Malakir Mire enters tapped.
{T}: Add {B}.

Malakir Rebirth

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Rebirth // Malakir Mire

Thrashing Brontodon

{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Crux of Fate

Choose one —
• Destroy all Dragon creatures.
• Destroy all non-Dragon creatures.

Overgrown Tomb

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

High Market

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

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.)

Liliana, Dreadhorde General

Whenever a creature you control dies, draw a card.
+1: Create a 2/2 black Zombie creature token.
−4: Each player sacrifices two creatures of their choice.
−9: Each opponent chooses a permanent they control of each permanent type and sacrifices the rest.

Nim Deathmantle

Equipped creature gets +2/+2, has intimidate, and is a black Zombie. (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a nontoken creature is put into your graveyard from the battlefield, you may pay {4}. If you do, return that card to the battlefield and attach Nim Deathmantle to it.
Equip {4}

Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Jungle Hollow

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

Sidisi, Undead Vizier

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

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}."

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.

Zulaport Cutthroat

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

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature of their choice.

Golgari Signet

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Entomb

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

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Forest

Viscera Seer

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

Swamp

Farhaven Elf

When Farhaven Elf enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature of their choice.

Wurmcoil Engine

Deathtouch, lifelink
When Wurmcoil Engine dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.

Hagra Broodpit

Hagra Broodpit enters tapped.
{T}: Add {B}.

Hagra Mauling

This spell costs {1} less to cast if an opponent controls no basic lands.
Destroy target creature.

Hagra Mauling // Hagra Broodpit

Sol Ring

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.

Golgari Charm

Choose one —
• All creatures get -1/-1 until end of turn.
• Destroy target enchantment.
• Regenerate each creature you control.

Fauna Shaman

{G}, {T}, Discard a creature card: Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Temple of Malady

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {G}.

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature of their choice.

Grim Backwoods

{T}: Add {C}.
{2}{B}{G}, {T}, Sacrifice a creature: Draw a card.

Deathcap Cultivator

{T}: Add {B} or {G}.
Delirium — Deathcap Cultivator has deathtouch as long as there are four or more card types among cards in your graveyard.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Command the Dreadhorde

Choose any number of target creature and/or planeswalker cards in graveyards. Command the Dreadhorde deals damage to you equal to the total mana value of those cards. Put them onto the battlefield under your control.

Buried Alive

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

Phyrexian Arena

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

Augur of Autumn

You may look at the top card of your library any time.
You may play lands from the top of your library.
Coven — As long as you control three or more creatures with different powers, you may cast creature spells from the top of your library.

Plaguecrafter

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

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.)

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Krav, the Unredeemed

Partner with Regna, the Redeemer (When this creature enters, target player may put Regna into their hand from their library, then shuffle.)
{B}, Sacrifice X creatures: Target player draws X cards and gains X life. Put X +1/+1 counters on Krav, the Unredeemed.

Bane of Progress

When Bane of Progress enters, destroy all artifacts and enchantments. Put a +1/+1 counter on Bane of Progress for each permanent destroyed this way.

Pitiless Plunderer

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

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.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Satyr Wayfinder

When Satyr Wayfinder enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

Birds of Paradise

Ashnod's Altar

Protean Hulk

When Protean Hulk dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

God-Eternal Bontu

Menace
When God-Eternal Bontu enters, sacrifice any number of other permanents, then draw that many cards.
When God-Eternal Bontu dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Gravecrawler

Gravecrawler can't block.
You may cast Gravecrawler from your graveyard as long as you control a Zombie.

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Sifter of Skulls

Devoid (This card has no color.)
Whenever another nontoken creature you control dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}." ({C} represents colorless mana.)

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Smothering Abomination

Devoid (This card has no color.)
Flying
At the beginning of your upkeep, sacrifice a creature.
Whenever you sacrifice a creature, draw a card.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.