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.

Torch Fiend

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

Evolving Wilds

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

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.

Rakdos Locket

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

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.

Night Incarnate

Deathtouch
When Night Incarnate leaves the battlefield, all creatures get -3/-3 until end of turn.
Evoke {3}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Fetid Imp

Flying
{B}: Fetid Imp gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Pestilence Demon

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

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.

Mindwrack Demon

Flying, trample
When Mindwrack Demon enters, mill four cards.
Delirium — At the beginning of your upkeep, you lose 4 life unless there are four or more card types among cards in your graveyard.

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.

Abnormal Endurance

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."

Charmbreaker Devils

At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, Charmbreaker Devils gets +4/+0 until end of turn.

Blasted Landscape

{T}: Add {C}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Command Tower

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

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.

Havoc Devils

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Unstable Obelisk

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

Star Compass

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

Demonfire

Demonfire deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead.
Hellbent — If you have no cards in hand, this spell can't be countered and the damage can't be prevented.

Eater of Hope

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

Havoc Demon

Flying
When Havoc Demon dies, all creatures get -5/-5 until end of turn.

Hedron Archive

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

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.

Cackling Imp

Dirge of Dread

All creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)
When you cycle Dirge of Dread, you may have target creature gain fear until end of turn.

Rakdos Signet

Terramorphic Expanse

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

Urborg Volcano

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

Carrion Imp

Flying
When Carrion Imp enters, you may exile target creature card from a graveyard. If you do, you gain 2 life.

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.

Sol Ring

Wildfire Devils

When Wildfire Devils enters and at the beginning of your upkeep, choose a player at random. That player exiles an instant or sorcery card from their graveyard. Copy that card. You may cast the copy without paying its mana cost.

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.

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.

Easy Prey

Destroy target creature with mana value 2 or less.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Supernatural Stamina

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.

Mountain

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.

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.

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.

Demon of Loathing

Flying, trample
Whenever Demon of Loathing deals combat damage to a player, that player sacrifices a creature.

Hidetsugu, Devouring Chaos

{B}, Sacrifice a creature: Scry 2.
{2}{R}, {T}: Exile the top card of your library. You may play that card this turn. When you exile a nonland card this way, Hidetsugu, Devouring Chaos deals damage equal to the exiled card's mana value to any target.

Dark Ritual

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.)

Demon of Catastrophes

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

Swamp

Bloodfell Caves

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

Apocalypse Demon

Flying
Apocalypse Demon's power and toughness are each equal to the number of cards in your graveyard.
At the beginning of your upkeep, tap Apocalypse Demon unless you sacrifice another creature.

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.

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.

Demonlord of Ashmouth

Flying
When Demonlord of Ashmouth enters, exile it unless you sacrifice another creature.
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.)

Expunge

Destroy target nonartifact, nonblack creature. It can't be regenerated.
Cycling {2} ({2}, Discard this card: Draw a card.)

Prismatic Lens

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

Demon Bolt

Demon Bolt deals 4 damage to target creature or planeswalker.
Foretell {R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Cinder Barrens

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

Rakdos Guildgate

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

Lorcan, Warlock Collector

Flying
Whenever a creature card is put into an opponent's graveyard from anywhere, you may pay life equal to its mana value. If you do, put it onto the battlefield under your control. It's a Warlock in addition to its other types.
If a Warlock you control would die, exile it instead.

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.)

Gang of Devils

When Gang of Devils dies, it deals 3 damage divided as you choose among one, two, or three targets.

Indulgent Tormentor

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

Unhallowed Pact

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

Hulking Devil

Devil's Play

Devil's Play deals X damage to any target.
Flashback {X}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Barren Moor

Barren Moor enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Demon's Jester

Flying
Hellbent — Demon's Jester gets +2/+1 as long as you have no cards in hand.

Harvester of Souls

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

Akoum Refuge

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

Death Pulse

Target creature gets -4/-4 until end of turn.
Cycling {1}{B}{B} ({1}{B}{B}, Discard this card: Draw a card.)
When you cycle Death Pulse, you may have target creature get -1/-1 until end of turn.

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.)

Demon of Wailing Agonies

Flying
Lieutenant — As long as you control your commander, Demon of Wailing Agonies gets +2/+2 and has "Whenever Demon of Wailing Agonies deals combat damage to a player, that player sacrifices a creature."

Cadaver Imp

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