Reef Worm

When Reef Worm dies, create a 3/3 blue Fish creature token with "When this creature dies, create a 6/6 blue Whale creature token with 'When this creature dies, create a 9/9 blue Kraken creature token.'"

Commander's Sphere

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

Peregrine Drake

Flying
When Peregrine Drake enters the battlefield, untap up to five lands.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Cloud of Faeries

Flying
When Cloud of Faeries enters the battlefield, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.

Arcane Signet

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

Countersquall

Counter target noncreature spell. Its controller loses 2 life.

Chittering Witch

When Chittering Witch enters the battlefield, create a number of 1/1 black Rat creature tokens equal to the number of opponents you have.
{1}{B}, Sacrifice a creature: Target creature gets -2/-2 until end of turn.

Counterspell

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Watcher for Tomorrow

Hideaway 4 (When this creature enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Watcher for Tomorrow enters the battlefield tapped.
When Watcher for Tomorrow leaves the battlefield, put the exiled card into its owner's hand.

Floating-Dream Zubera

When Floating-Dream Zubera dies, draw a card for each Zubera that died this turn.

Ambuscade Shaman

Whenever Ambuscade Shaman or another creature enters the battlefield under your control, that creature gets +2/+2 until end of turn.
Dash {3}{B} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Rakshasa Debaser

Whenever Rakshasa Debaser attacks, put target creature card from defending player's graveyard onto the battlefield under your control.
Encore {6}{B}{B} ({6}{B}{B}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Laquatus's Champion

When Laquatus's Champion enters the battlefield, target player loses 6 life.
When Laquatus's Champion leaves the battlefield, that player gains 6 life.
{B}: Regenerate Laquatus's Champion.

Araumi of the Dead Tide

{T}, Exile cards from your graveyard equal to the number of opponents you have: Target creature card in your graveyard gains encore until end of turn. The encore cost is equal to its mana cost. (Exile the creature card and pay its mana cost: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Deceiver Exarch

Flash (You may cast this spell any time you could cast an instant.)
When Deceiver Exarch enters the battlefield, choose one —
• Untap target permanent you control.
• Tap target permanent an opponent controls.

Grave Titan

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

Atris, Oracle of Half-Truths

Menace
When Atris, Oracle of Half-Truths enters the battlefield, target opponent looks at the top three cards of your library and separates them into a face-down pile and a face-up pile. Put one pile into your hand and the other into your graveyard.

Hagra Diabolist

Whenever Hagra Diabolist or another Ally enters the battlefield under your control, you may have target player lose life equal to the number of Allies you control.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Black Market

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.

Mesmerizing Benthid

When Mesmerizing Benthid enters the battlefield, create two 0/2 blue Illusion creature tokens with "Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step."
Mesmerizing Benthid has hexproof as long as you control an Illusion.

Mulldrifter

Flying
When Mulldrifter enters the battlefield, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Woe Strider

When Woe Strider enters the battlefield, create a 0/1 white Goat creature token.
Sacrifice another creature: Scry 1.
Escape—{3}{B}{B}, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Woe Strider escapes with two +1/+1 counters on it.

Renegade Doppelganger

Whenever another creature enters the battlefield under your control, you may have Renegade Doppelganger become a copy of that creature until end of turn. (If it does, it loses this ability for the rest of the 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 the battlefield.)

Bazaar Trademage

Flying
When Bazaar Trademage enters the battlefield, draw two cards, then discard three cards.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Whispering Madness

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Careful Study

Agent of Treachery

When Agent of Treachery enters the battlefield, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Millikin

Stitcher's Supplier

When Stitcher's Supplier enters the battlefield or dies, mill three cards.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Massacre Wurm

When Massacre Wurm enters the battlefield, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Corridor Monitor

When Corridor Monitor enters the battlefield, untap target artifact or creature you control.

Drown in the Loch

Choose one —
• Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard.
• Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

Mana Crypt

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}.

Ancient Excavation

Draw cards equal to the number of cards in your hand, then discard a card for each card drawn this way.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Thirst for Knowledge

Draw three cards. Then discard two cards unless you discard an artifact card.

Demon's Disciple

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

Ravenous Chupacabra

When Ravenous Chupacabra enters the battlefield, destroy target creature an opponent controls.

Thassa's Oracle

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Sol Ring

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Plaguecrafter

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

Perpetual Timepiece

{T}: Mill two cards.
{2}, Exile Perpetual Timepiece: Shuffle any number of target cards from your graveyard into your library.

Forbidden Alchemy

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sower of Discord

Flying
As Sower of Discord enters the battlefield, choose two players.
Whenever damage is dealt to one of the chosen players, the other chosen player also loses that much life.

Vindictive Lich

When Vindictive Lich dies, choose one or more. Each mode must target a different player.
• Target opponent sacrifices a creature.
• Target opponent discards two cards.
• Target opponent loses 5 life.

Compulsive Research

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Amphin Mutineer

When Amphin Mutineer enters the battlefield, exile up to one target non-Salamander creature. That creature's controller creates a 4/3 blue Salamander Warrior creature token.
Encore {4}{U}{U} ({4}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Snow-Covered Swamp

Shriekmaw

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Shriekmaw enters the battlefield, 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 the battlefield.)

Merfolk Looter

Dimir Signet

Champion of Wits

When Champion of Wits enters the battlefield, you may draw cards equal to its power. If you do, discard two cards.
Eternalize {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Snake Wizard with no mana cost. Eternalize only as a sorcery.)