When Abyssal Gatekeeper dies, each player sacrifices a creature.

Flying, trample

You can't win the game and your opponents can't lose the game.

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Whenever a player casts a creature spell, that player sacrifices a permanent unless they pay {1}.

Enchant creature card in a graveyard

When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.

Enchanted creature gets -1/-0.

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

Sacrifice a creature: Add {C}{C}.

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

{T}: Add {B}.

{T}: Add {R}.

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

({T}: Add {B} or {R}.)

As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Menace, indestructible

Bontu the Glorified can't attack or block unless a creature died under your control this turn.

{1}{B}, Sacrifice another creature: Scry 1. Each opponent loses 1 life and you gain 1 life.

Flying

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

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

Create X 0/1 black Insect creature tokens, where X is the sacrificed creature's power.

{T}: Add {C}.

{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

{T}: Add {U}.

{T}: Add {B}.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

When Commander Greven il-Vec enters the battlefield, sacrifice a creature.

You may have Copy Artifact enter the battlefield as a copy of any artifact on the battlefield, except it's an enchantment in addition to its other types.

Crovax the Cursed enters the battlefield with four +1/+1 counters on it.

At the beginning of your upkeep, you may sacrifice a creature. If you do, put a +1/+1 counter on Crovax. If you don't, remove a +1/+1 counter from Crovax.

{B}: Crovax gains flying until end of turn.

Add {B}{B}{B}.

Flying, trample

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

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

{T}: Add {C}.

{1}{U}{R}, {T}: Draw a card, then discard a card.

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.

Flash

Whenever a creature you control dies, each opponent sacrifices a creature.

Flash

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.

{T}: Add {B} or {R}.

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.

{T}: Add {U} or {B}.

Flash

This spell costs {1} less to cast for each attacking creature you control.

When Embercleave enters the battlefield, attach it to target creature you control.

Equipped creature gets +1/+1 and has double strike and trample.

Equip {3}

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.

Indestructible

As long as your devotion to black is less than five, Erebos isn't a creature.

Whenever another creature you control dies, you may pay 2 life. If you do, draw a card.

{1}{B}, Sacrifice another creature: Target creature gets -2/-1 until end of turn.

Flying

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

{T}, Pay 1 life: Add {U} or {R}.

{1}, {T}, Sacrifice Fiery Islet: Draw a card.

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

{B}, {T}, Sacrifice another creature: Create X 2/2 black Zombie creature tokens, where X is the sacrificed creature's power.

{T}: Add three mana of any one color.

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

Deathtouch

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

{T}: Add {C}.

{B/R}, {T}: Add {B}{B}, {B}{R}, or {R}{R}.

Grim Monolith doesn't untap during your untap step.

{T}: Add {C}{C}{C}.

{4}: Untap Grim Monolith.

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

{2}, Sacrifice a nontoken permanent: Draw a card.

Each player sacrifices a creature.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

Look at the top five cards of your library. As many times as you choose, you may pay 1 life, put those cards on the bottom of your library in any order, then look at the top five cards of your library. Then shuffle and put the last cards you looked at this way on top in any order.

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.

{T}: Add {C}{C}.

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Mana Vault doesn't untap during your untap step.

At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.

At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.

{T}: Add {C}{C}{C}.

{T}: Choose a color of a permanent you control. Add one mana of that color.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Whenever a Human deals damage to you, destroy it.

Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying 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.)

Indestructible

As long as your devotion to black and red is less than seven, Mogis isn't a creature.

At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature.

({T}: Add {R}.)

({T}: Add {R}.)

({T}: Add {R}.)

({T}: Add {R}.)

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Each player sacrifices six creatures. You create six tapped 2/2 black Zombie creature tokens.

When Oubliette enters the battlefield, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

All creatures have "At the beginning of your upkeep, sacrifice this creature unless you pay {1}."

Search your library for a sorcery card, reveal it, then shuffle and put that card on top.

Sacrifice a creature: Add one mana of any color.

Trample

When Phyrexian Dreadnought enters the battlefield, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

{T}: Add {C}.

{T}, Sacrifice a creature: Add {B}{B}.

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Flying, trample

Pay 2 life, Sacrifice another creature: Search your library for a card, put that card into your hand, then shuffle.

{T}: Add {U}. If you played a land this turn, add {B} instead.

{T}: Add {U}.

{T}: Add {R}.

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

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

When Sengir Autocrat leaves the battlefield, exile all Serf tokens.

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.

{T}: Add {C}.

{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

{T}: Add {C}{C}.

Spirebluff Canal enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {U} or {R}.

({T}: Add {U} or {R}.)

As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.

{T}: Add {U} or {R}.

{T}: Add {C}.

{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

{T}: Add {C}.

{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

Exile the top card of your library. You may put that card into your hand unless it has the same name as another card exiled this way. Repeat this process until you put a card into your hand or you exile two cards with the same name, whichever comes first.

Target creature gains double strike until end of turn.

Ferocious -- That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Menace

Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

{T}: Target player loses 3 life unless they sacrifice a nonland permanent or discard a card.

{3}{B}: Untap Tergrid's Lantern.

+2: Create two 0/1 black Thrull creature tokens.

+1: You may sacrifice another creature or planeswalker. If you do, draw two cards, then draw another card if the sacrificed permanent was a commander.

-10: Gain control of all commanders. Put all commanders from the command zone onto the battlefield under your control.

Tevesh Szat, Doom of Fools can be your commander.

Partner

Whenever a creature with a -1/-1 counter on it dies, draw a card.

{1}{B}{R}: Put a -1/-1 counter on another target creature.

When The Scorpion God dies, return it to its owner's hand at the beginning of the next end step.

Haste

Whenever Thraximundar attacks, defending player sacrifices a creature.

Whenever a player sacrifices a creature, you may put a +1/+1 counter on Thraximundar.

Training Center enters the battlefield tapped unless you have two or more opponents.

{T}: Add {U} or {R}.

{T}: Add {C}.

{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Equipped creature gets +3/+3 and has first strike.

Whenever a creature dealt damage by equipped creature this turn dies, you may exile that card. If you do, create a 2/2 black Zombie creature token.

Equip {2}

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

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.)

As long as the top card of your graveyard is a creature card, Volrath's Shapeshifter has the full text of that card and has the text "{2}: Discard a card." (Volrath's Shapeshifter has that card's name, mana cost, color, types, abilities, power, and toughness.)

{2}: Discard a card.

({T}: Add {U} or {B}.)

As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Each player discards their hand, then draws seven cards.