Toxrill, the Corrosive (black-blue)

Flying

Whenever Archon of Cruelty enters the battlefield or attacks, target opponent sacrifices a creature or planeswalker, discards a card, and loses 3 life. You draw a card and gain 3 life.

Whenever Ashling, the Extinguisher deals combat damage to a player, choose target creature that player controls. The player sacrifices that creature.

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.

{T}, Sacrifice another black creature: Draw a card.

When Banewhip Punisher enters the battlefield, you may put a -1/-1 counter on target creature.

{B}, Sacrifice Banewhip Punisher: Destroy target creature that has a -1/-1 counter on it.

Whenever a creature dies, put a charge counter on Black Market.

At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Whenever a creature dies, if it had a -1/-1 counter on it, put a -1/-1 counter on target creature.

Flying

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

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

{T}: Add {C}.

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

As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped.

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

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

When Contagion Engine enters the battlefield, put a -1/-1 counter on each creature target player controls.

{4}, {T}: Proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Black creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)

Counter target spell.

Counter target noncreature spell. Its controller loses 2 life.

At the beginning of your upkeep, destroy target creature with a -1/-1 counter on it.

Choose two —

• Counter target spell.

• Return target permanent to its owner's hand.

• Tap all creatures your opponents control.

• Draw a card.

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.

Counter target spell. If an artifact or creature spell is countered this way, put that card onto the battlefield under your control instead of into its owner's graveyard.

Flash

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

{1}, {T}: Add {U}{B}.

Whenever a blue creature enters the battlefield under your control, you may have target player draw a card.

Whenever a black creature enters the battlefield under your control, you may have target player discard a card.

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Dismal Backwater enters the battlefield tapped.

When Dismal Backwater enters the battlefield, you gain 1 life.

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

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

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

Whenever another creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Whenever you sacrifice a token, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Flying, lifelink, hexproof from planeswalkers

Boast — {1}{B}, Sacrifice a creature: Each opponent sacrifices a creature or planeswalker. (Activate only if this creature attacked this turn and only once each turn.)

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

Fetid Pools enters the battlefield tapped.

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

If you control a commander, you may cast this spell without paying its mana cost.

Counter target noncreature spell.

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

{X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.

Ghastlord of Fugue can't be blocked.

Whenever Ghastlord of Fugue deals combat damage to a player, that player reveals their hand. You choose a card from it. That player exiles that card.

{4}, {T}: Put a -1/-1 counter on target creature.

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

Flying

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

When Goremand enters the battlefield, each opponent sacrifices a creature.

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

Put a -1/-1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Halimar Depths enters the battlefield tapped.

When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order.

{T}: Add {U}.

Put a -1/-1 counter on target creature, two -1/-1 counters on another target creature, and three -1/-1 counters on a third target creature.

({T}: Add {U}.)

{T}: Add {C}.

{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Menace

Whenever you sacrifice a creature, you may pay {U/B}. If you do, draw a card. ({U/B} can be paid with either {U} or {B}.)

{1}, Sacrifice a creature: Kels, Fight Fixer gains indestructible until end of turn.

Creatures you control have flying.

Spells can't be countered.

Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

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.

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

At the beginning of your upkeep, put a -1/-1 counter on each nonblack creature.

Mistvault Bridge enters the battlefield tapped.

Indestructible

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

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Mortuary Mire enters the battlefield tapped.

When Mortuary Mire enters the battlefield, you may put target creature card from your graveyard on top of your library.

{T}: Add {B}.

Choose three. You may choose the same mode more than once.

• Counter target spell unless its controller pays {3}.

• Return target creature to its owner's hand.

• Draw a card.

Flying

Whenever a creature you control deals combat damage to a player, put that many +1/+1 counters on it.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Whenever a creature an opponent controls with a -1/-1 counter on it dies, you may return that card to the battlefield under your control.

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

Flying, deathtouch, lifelink

Nighthawk Scavenger's power is equal to 1 plus the number of card types among cards in your opponents' graveyards. (Cards in graveyards have only the characteristics of their front face.)

{T}: Add {C}.

{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

At the beginning of each upkeep, if you control no Snakes, create a 1/1 black Snake creature token with deathtouch.

Other black creatures you control get +1/+1.

{2}{B}, {T}: Another target black creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

You have no maximum hand size.

{T}: Add {C}.

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.

Put all creature cards from all graveyards onto the battlefield under your control.

Flying

Whenever you sacrifice a creature, target opponent sacrifices a creature.

As an additional cost to cast this spell, put a -1/-1 counter on a creature you control.

Draw two cards.

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands.

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

Deathtouch

Exploit (When this creature enters the battlefield, you may sacrifice a creature.)

When Sidisi, Undead Vizier exploits a creature, you may search your library for a card, put it into your hand, then shuffle.

Devoid (This card has no color.)

Whenever a land enters the battlefield under an opponent's control, that player exiles the top two cards of their library and you draw two cards.

Whenever Sludge Monster enters the battlefield or attacks, put a slime counter on up to one other target creature.

Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.

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

Counter target activated or triggered ability. (Mana abilities can't be targeted.)

Exile all other spells and counter all abilities.

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

Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

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.

When The Meathook Massacre enters the battlefield, each creature gets -X/-X until end of turn.

Whenever a creature you control dies, each opponent loses 1 life.

Whenever a creature an opponent controls dies, you gain 1 life.

At the beginning of each end step, put a slime counter on each creature you don't control.

Creatures you don't control get -1/-1 for each slime counter on them.

Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token.

{U}{B}, Sacrifice a Slug: Draw a card.

Choose artifact, creature, or land. Tap all untapped permanents of the chosen type target player controls, or untap all tapped permanents of that type that player controls.

{T}: Create a Treasure token. Activate only if a creature died this turn. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

{T}: Add {C}.

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

Counter target noncreature spell. Untap up to three lands.

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

Other creatures you control have intimidate.

Whenever Vela the Night-Clad or another creature you control leaves the battlefield, each opponent loses 1 life.

{T}: Add {C}.

{1}{B}, {T}: Put target creature card from your graveyard on top of your library.

({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.

Haste

Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.

Sacrifice another creature: Yahenni gains indestructible until end of turn.