Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Dictate of Erebos

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

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Skullclamp

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

Ashnod's Altar

Vampiric Tutor

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

Mortal Combat

At the beginning of your upkeep, if twenty or more creature cards are in your graveyard, you win the game.

Forever Young

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

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}.'"

Bloodgift Demon

Flying
At the beginning of your upkeep, target player draws a card and loses 1 life.

Rotlung Reanimator

Whenever Rotlung Reanimator or another Cleric dies, create a 2/2 black Zombie creature token.

Rune-Scarred Demon

Flying
When this creature enters, search your library for a card, put it into your hand, then shuffle.

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.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Liliana's Contract

When Liliana's Contract enters, you draw four cards and you lose 4 life.
At the beginning of your upkeep, if you control four or more Demons with different names, you win the game.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Shadow-Rite Priest

Other Clerics you control get +1/+1.
{3}{B}{B}, {T}, Sacrifice another Cleric: Search your library for a black creature card, put it onto the battlefield, then shuffle.

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.)

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Swamp

Jet Medallion

Black spells you cast cost {1} less to cast.

Taborax, Hope's Demise

Flying
Taborax, Hope's Demise has lifelink as long as it has five or more +1/+1 counters on it.
Whenever another nontoken creature you control dies, put a +1/+1 counter on Taborax. If that creature was a Cleric, you may draw a card. If you do, you lose 1 life.

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.

Reaper from the Abyss

Flying
Morbid — At the beginning of each end step, if a creature died this turn, destroy target non-Demon creature.

Abhorrent Overlord

Flying
When Abhorrent Overlord enters, create a number of 1/1 black Harpy creature tokens with flying equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
At the beginning of your upkeep, sacrifice a creature.

Zulaport Cutthroat

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

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Nightmare Shepherd

Flying
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and it's a Nightmare in addition to its other types.

Dreadfeast Demon

Flying
At the beginning of your end step, sacrifice a non-Demon creature. If you do, create a token that's a copy of Dreadfeast Demon.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Great Unclean One

Reverberating Summons — At the beginning of your end step, each opponent loses 2 life. Then for each opponent who has less life than you, create a 1/3 black Demon creature token named Plaguebearer of Nurgle.

Grave Pact

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

Drivnod, Carnage Dominus

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{B/P}{B/P}, Exile three creature cards from your graveyard: Put an indestructible counter on Drivnod, Carnage Dominus. ({B/P} can be paid with either {B} or 2 life.)

Shadowborn Apostle

A deck can have any number of cards named Shadowborn Apostle.
{B}, Sacrifice six creatures named Shadowborn Apostle: Search your library for a Demon creature card, put it onto the battlefield, then shuffle.

Overwhelming Remorse

This spell costs {1} less to cast for each creature card in your graveyard.
Exile target creature or planeswalker.

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Blood Artist

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

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.