Swamp

Sengir, the Dark Baron

Flying
Whenever another creature dies, put two +1/+1 counters on Sengir, the Dark Baron.
Whenever another player loses the game, you gain life equal to that player's life total as the turn began.
Partner (You can have two commanders if both have partner.)

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.)

Malevolent Awakening

{1}{B}{B}, Sacrifice a creature: Return target creature card from your graveyard to your hand.

Gruesome Fate

Each opponent loses 1 life for each creature you control.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fallen Angel

Flying
Sacrifice a creature: Fallen Angel gets +2/+1 until end of turn.

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."

Butcher of Malakir

Flying
Whenever Butcher of Malakir or another creature you control dies, each opponent sacrifices a creature of their choice.

Plaguecrafter

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Liliana's Standard Bearer

Flash
When Liliana's Standard Bearer enters, draw X cards, where X is the number of creatures that died under your control this turn.

Bloodthrone Vampire

Sacrifice a creature: Bloodthrone Vampire gets +2/+2 until end of turn.

Ebony Fly

Ebony Fly enters tapped.
{T}: Add {C}.
{4}: Roll a d6. Until end of turn, you may have Ebony Fly become an X/X Insect artifact creature with flying, where X is the result.
Whenever Ebony Fly attacks, another target attacking creature gains flying until end of turn.

Demon's Disciple

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

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.

Endrek Sahr, Master Breeder

Whenever you cast a creature spell, create X 1/1 black Thrull creature tokens, where X is that spell's mana value.
When you control seven or more Thrulls, sacrifice Endrek Sahr, Master Breeder.

Minions' Murmurs

You draw X cards and you lose X life, where X is the number of creatures you control.

Ecologist's Terrarium

When Ecologist's Terrarium enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, {T}, Sacrifice Ecologist's Terrarium: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Orc Sureshot

Whenever another creature you control enters, target creature an opponent controls gets -1/-1 until end of turn.

Spark Harvest

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Destroy target creature or planeswalker.

Orazca Relic

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
{T}: Add {C}.
{T}, Sacrifice Orazca Relic: You gain 3 life and draw a card. Activate only if you have the city's blessing.

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Fell Stinger

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When Fell Stinger exploits a creature, target player draws two cards and loses 2 life.

Nadier's Nightblade

Whenever a token you control leaves the battlefield, each opponent loses 1 life and you gain 1 life.

Sisay's Ring

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.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Dark Privilege

Enchant creature
Enchanted creature gets +1/+1.
Sacrifice a creature: Regenerate enchanted creature.

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.)

Ornithopter of Paradise

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.

Vampire Aristocrat

Sacrifice a creature: Vampire Aristocrat gets +2/+2 until end of turn.

Abnormal Endurance

Nantuko Husk

Sacrifice a creature: Nantuko Husk gets +2/+2 until end of turn.

Bankrupt in Blood

As an additional cost to cast this spell, sacrifice two creatures.
Draw three cards.

Phyrexian Plaguelord

{T}, Sacrifice Phyrexian Plaguelord: Target creature gets -4/-4 until end of turn.
Sacrifice a creature: Target creature gets -1/-1 until end of turn.

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.

Flesh-Eater Imp

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Sacrifice a creature: Flesh-Eater Imp gets +1/+1 until end of turn.

Fallen Ideal

Enchant creature
Enchanted creature has flying and "Sacrifice a creature: This creature gets +2/+1 until end of turn."
When Fallen Ideal is put into a graveyard from the battlefield, return Fallen Ideal to its owner's hand.

Village Rites

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

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Tar Fiend

Devour 2 (As this enters, you may sacrifice any number of creatures. This creature enters with twice that many +1/+1 counters on it.)
When Tar Fiend enters, target player discards a card for each creature it devoured.

Culling Dais

{T}, Sacrifice a creature: Put a charge counter on Culling Dais.
{1}, Sacrifice Culling Dais: Draw a card for each charge counter on Culling Dais.

Professor's Warning

Choose one —
• Put a +1/+1 counter on target creature.
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Altar's Reap

Skirsdag High Priest

Morbid — {T}, Tap two untapped creatures you control: Create a 5/5 black Demon creature token with flying. Activate only if a creature died this turn.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Sengir Autocrat

When Sengir Autocrat enters, create three 0/1 black Serf creature tokens.
When Sengir Autocrat leaves the battlefield, exile all Serf tokens.

Gravelighter

Flying
When Gravelighter enters, draw a card if a creature died this turn. Otherwise, each player sacrifices a creature of their choice.

Szat's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Each opponent sacrifices a creature they control with the greatest power.
• Exile all opponents' graveyards, then create X 0/1 black Thrull creature tokens, where X is the greatest power among creature cards exiled this way.

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.

Shriekmaw

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Shriekmaw enters, destroy target nonartifact, nonblack creature.
Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Nightmare Unmaking

Choose one —
• Exile each creature with power greater than the number of cards in your hand.
• Exile each creature with power less than the number of cards in your hand.

Whisper, Blood Liturgist

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

Fleshbag Marauder

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

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Viscera Seer

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

Eliminate the Competition

As an additional cost to cast this spell, sacrifice X creatures.
Destroy X target creatures.

Soul Exchange

As an additional cost to cast this spell, exile a creature you control.
Return target creature card from your graveyard to the battlefield. Put a +2/+2 counter on that creature if the exiled creature was a Thrull.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Undying Malice

Nadier, Agent of the Duskenel

Whenever a token you control leaves the battlefield, put a +1/+1 counter on Nadier, Agent of the Duskenel.
When Nadier leaves the battlefield, create a number of 1/1 green Elf Warrior creature tokens equal to its power.
Partner (You can have two commanders if both have partner.)