When Abyssal Gatekeeper dies, each player sacrifices a creature.

+1: Each opponent discards a card and loses 2 life.

-3: Gain control of target creature until end of turn. Untap it. It gains haste until end of turn. Sacrifice it at the beginning of the next end step if it has mana value 3 or less.

-8: Each opponent loses life equal to the number of cards in their graveyard.

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

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

When Bastion of Remembrance enters the battlefield, create a 1/1 white Human Soldier creature token.

Whenever a creature you control dies, each opponent 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.

{2}, {T}: Add {B} for each Swamp you control.

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

Canyon Slough enters the battlefield tapped.

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

Each player sacrifices a permanent.

Whenever another creature dies, you may gain 1 life.

When Demon's Disciple enters the battlefield, each player sacrifices a creature or planeswalker.

Flash

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

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

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

When Fleshbag Marauder enters the battlefield, each player sacrifices a creature.

Each player loses half their life, then discards half the cards in their hand, then sacrifices half the creatures they control. Round up each time.

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

Each player sacrifices a creature.

Jeska, Thrice Reborn enters the battlefield with a loyalty counter on her for each time you've cast a commander from the command zone this game.

0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead.

-X: Jeska, Thrice Reborn deals X damage to each of up to three targets.

Jeska, Thrice Reborn can be your commander.

Partner

For each creature, its controller sacrifices it unless they pay X life.

When Kroxa enters the battlefield, sacrifice it unless it escaped.

Whenever Kroxa enters the battlefield or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.

Escape--{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Whenever a permanent other than Last Laugh is put into a graveyard from the battlefield, Last Laugh deals 1 damage to each creature and each player.

When no creatures are on the battlefield, sacrifice Last Laugh.

({T}: Add {B}.)

Leechridden Swamp enters the battlefield tapped.

{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

+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}.'"

+1: Each player discards a card.

-2: Target player sacrifices a creature.

-6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.

Each opponent sacrifices a creature. If you control a Liliana planeswalker, each opponent also discards a card.

Whenever a creature you control dies, draw a card.

+1: Create a 2/2 black Zombie creature token.

-4: Each player sacrifices two creatures.

-9: Each opponent chooses a permanent they control of each permanent type and sacrifices the rest.

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Suspend 3--{2}{B}{B}

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

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

Whenever a player sacrifices a permanent, Mayhem Devil deals 1 damage to any target.

When Merciless Executioner enters the battlefield, each player sacrifices a creature.

Each opponent sacrifices a creature or enchantment.

({T}: Add {R}.)

({T}: Add {R}.)

When Plaguecrafter enters the battlefield, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

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

Magecraft -- Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.

+1: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

-3: Each opponent sacrifices a creature with the greatest power among creatures that player controls.

-8: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.

Flying

Whenever a creature an opponent controls dies, you may gain 3 life.

Whenever an opponent discards a card, you may gain 3 life.

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

When you cast this spell, copy it for each time you've cast your commander from the command zone this game.

Each opponent sacrifices a creature. Each opponent who can't loses half their life, rounded up.

Each player loses 1 life, discards a card, sacrifices a creature, then sacrifices a land.

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

Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

Choose one. If you control a commander as you cast this spell, you may choose both.

• 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.

{T}: Add {C}.

{T}: Add {B} or {R}. Activate only if you control a Swamp.

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

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

Will of the council -- Starting with you, each player votes for death or torture. If death gets more votes, each opponent sacrifices a creature. If torture gets more votes or the vote is tied, each opponent loses 4 life.

Each land is a Swamp in addition to its other land types.

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

For each player, choose friend or foe. Each friend returns a creature card from their graveyard to their hand. Each foe sacrifices a creature they control.

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)

Each opponent sacrifices a creature. If you have the city's blessing, instead each opponent sacrifices half the creatures they control, rounded up.

({T}: Add {B}.)

Witch's Cottage enters the battlefield tapped unless you control three or more other Swamps.

When Witch's Cottage enters the battlefield untapped, you may put target creature card from your graveyard on top of your library.

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