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.

Rakdos, the Showstopper

Flying, trample
When Rakdos, the Showstopper enters, flip a coin for each creature that isn't a Demon, Devil, or Imp. Destroy each creature whose coin comes up tails.

Sire of Insanity

At the beginning of each end step, each player discards their hand.

Kothophed, Soul Hoarder

Flying
Whenever a permanent owned by another player is put into a graveyard from the battlefield, you draw a card and you lose 1 life.

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.)

Herald of Torment

Bestow {3}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
At the beginning of your upkeep, you lose 1 life.
Enchanted creature gets +3/+3 and has flying.

Mind Stone

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

Grixis Panorama

{T}: Add {C}.
{1}, {T}, Sacrifice Grixis Panorama: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Herald of Anguish

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Flying
At the beginning of your end step, each opponent discards a card.
{1}{B}, Sacrifice an artifact: Target creature gets -2/-2 until end of turn.

Torch Fiend

{R}, Sacrifice Torch Fiend: Destroy target artifact.

Changeling Berserker

Changeling (This card is every creature type.)
Haste
Champion a creature (When this enters, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)

Harvester of Souls

Deathtouch
Whenever another nontoken creature dies, you may draw a card.

Rakdos Signet

Bloodfell Caves

Bloodfell Caves enters tapped.
When Bloodfell Caves enters, you gain 1 life.
{T}: Add {B} or {R}.

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Sin Prodder

Menace
At the beginning of your upkeep, reveal the top card of your library. Any opponent may have you put that card into your graveyard. If a player does, Sin Prodder deals damage to that player equal to that card's mana value. Otherwise, put that card into your hand.

Shadows of the Past

Whenever a creature dies, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{4}{B}: Each opponent loses 2 life and you gain 2 life. Activate only if there are four or more creature cards in your graveyard.

Grinning Demon

At the beginning of your upkeep, you lose 2 life.
Morph {2}{B}{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.)

Indulgent Tormentor

Flying
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature or pays 3 life.

Nefarox, Overlord of Grixis

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever Nefarox, Overlord of Grixis attacks alone, defending player sacrifices a creature.

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Unhallowed Pact

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

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Chaos Imps

Flying
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
Chaos Imps has trample as long as it has a +1/+1 counter on it.

Rakdos Guildgate

Rakdos Guildgate enters tapped.
{T}: Add {B} or {R}.

Rakdos Locket

{T}: Add {B} or {R}.
{B/R}{B/R}{B/R}{B/R}, {T}, Sacrifice Rakdos Locket: Draw two cards.

Pestilence Demon

Flying
{B}: Pestilence Demon deals 1 damage to each creature and each player.

Oni of Wild Places

Haste
At the beginning of your upkeep, return a red creature you control to its owner's hand.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

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.

Archfiend of Ifnir

Flying
Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.
Cycling {2} ({2}, Discard this card: Draw a card.)

Urborg Volcano

Urborg Volcano enters tapped.
{T}: Add {B} or {R}.

Terramorphic Expanse

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

Akoum Refuge

Akoum Refuge enters tapped.
When Akoum Refuge enters, you gain 1 life.
{T}: Add {B} or {R}.

Reiver Demon

Flying
When Reiver Demon enters, if you cast it from your hand, destroy all nonartifact, nonblack creatures. They can't be regenerated.

Archdemon of Paliano

Draft Archdemon of Paliano face up.
As long as Archdemon of Paliano is face up during the draft, you can't look at booster packs and must draft cards at random. After you draft three cards this way, turn Archdemon of Paliano face down. (You may look at cards as you draft them.)
Flying

Shade's Form

Enchant creature
Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."
When enchanted creature dies, return that card to the battlefield under your control.

Evolving Wilds

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

Demonlord Belzenlok

Flying, trample
When Demonlord Belzenlok enters, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's mana value is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.

Stronghold Overseer

Flying
Shadow (This creature can block or be blocked by only creatures with shadow.)
{B}{B}: Creatures with shadow get +1/+0 until end of turn and creatures without shadow get -1/-0 until end of turn.

Rocky Tar Pit

Rocky Tar Pit enters tapped.
{T}, Sacrifice Rocky Tar Pit: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Cold Storage

{3}: Exile target creature you control.
Sacrifice Cold Storage: Return each creature card exiled with Cold Storage to the battlefield under your control.

Desecration Demon

Flying
At the beginning of each combat, any opponent may sacrifice a creature. If a player does, tap Desecration Demon and put a +1/+1 counter on it.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Shadowborn Demon

Flying
When Shadowborn Demon enters, destroy target non-Demon creature.
At the beginning of your upkeep, if there are fewer than six creature cards in your graveyard, sacrifice a creature.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Demon of Catastrophes

As an additional cost to cast this spell, sacrifice a creature.
Flying, trample

Jund Panorama

{T}: Add {C}.
{1}, {T}, Sacrifice Jund Panorama: Search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle.

Voyager Staff

{2}, Sacrifice Voyager Staff: Exile target creature. Return the exiled card to the battlefield under its owner's control at the beginning of the next end step.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Halo Hunter

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
When Halo Hunter enters, destroy target Angel.

Blood Speaker

At the beginning of your upkeep, you may sacrifice Blood Speaker. If you do, search your library for a Demon card, reveal that card, put it into your hand, then shuffle.
Whenever a Demon enters under your control, return Blood Speaker from your graveyard to your hand.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

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.

Eater of Hope

Flying
{B}, Sacrifice another creature: Regenerate Eater of Hope.
{2}{B}, Sacrifice two other creatures: Destroy target creature.

Bloodgift Demon

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

Mountain

Revel in Riches

Whenever a creature an opponent controls dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.

Cadaver Imp

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

Maddening Imp

Flying
{T}: Non-Wall creatures the active player controls attack this turn if able. At the beginning of the next end step, destroy each of those creatures that didn't attack this turn. Activate only during an opponent's turn and only before combat.

Star Compass

Star Compass enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Unstable Obelisk

{T}: Add {C}.
{7}, {T}, Sacrifice Unstable Obelisk: Destroy target permanent.

Reaper from the Abyss

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

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.

Undying Evil

Target creature gains undying until end of turn. (When it 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.)

Synod Sanctum

{2}, {T}: Exile target permanent you control.
{2}, Sacrifice Synod Sanctum: Return all cards exiled with Synod Sanctum to the battlefield under your control.

Warped Landscape

{T}: Add {C}.
{2}, {T}, Sacrifice Warped Landscape: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sphere of the Suns

Sphere of the Suns enters tapped and with three charge counters on it.
{T}, Remove a charge counter from Sphere of the Suns: Add one mana of any color.

Nettling Imp

{T}: Choose target non-Wall creature the active player has controlled continuously since the beginning of the turn. That creature attacks this turn if able. Destroy it at the beginning of the next end step if it didn't attack this turn. Activate only during an opponent's turn, before attackers are declared.

Abnormal Endurance

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Cinder Barrens

Cinder Barrens enters tapped.
{T}: Add {B} or {R}.

Swamp

Demon of Dark Schemes

Flying
When Demon of Dark Schemes enters, all other creatures get -2/-2 until end of turn.
Whenever another creature dies, you get {E} (an energy counter).
{2}{B}, Pay {E}{E}{E}{E}: Put target creature card from a graveyard onto the battlefield under your control tapped.

Aether Hub

When Aether Hub enters, you get {E} (an energy counter).
{T}: Add {C}.
{T}, Pay {E}: Add one mana of any color.

Hellrider

Haste
Whenever a creature you control attacks, Hellrider deals 1 damage to the player or planeswalker it's attacking.