Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Dismiss

Darkwater Catacombs

Sky Diamond

Reach Through Mists

Peek

Look at target player's hand.
Draw a card.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Coastal Breach

Undaunted (This spell costs {1} less to cast for each opponent.)
Return all nonland permanents to their owners' hands.

Price of Fame

This spell costs {2} less to cast if it targets a legendary creature.
Destroy target creature.
Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Sol Ring

Kagemaro, First to Suffer

Kagemaro, First to Suffer's power and toughness are each equal to the number of cards in your hand.
{B}, Sacrifice Kagemaro: All creatures get -X/-X until end of turn, where X is the number of cards in your hand.

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Dimir Signet

Footbottom Feast

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Hydrolash

Attacking creatures get -2/-0 until end of turn.
Draw a card.

Deliberate

Snap

Return target creature to its owner's hand. Untap up to two lands.

Devastation Tide

Return all nonland permanents to their owners' hands.
Miracle {1}{U} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Vivid Creek

Vivid Creek enters tapped with two charge counters on it.
{T}: Add {U}.
{T}, Remove a charge counter from Vivid Creek: Add one mana of any color.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Force of Despair

If it's not your turn, you may exile a black card from your hand rather than pay this spell's mana cost.
Destroy all creatures that entered this turn.

Uncomfortable Chill

Creatures your opponents control get -2/-0 until end of turn.
Draw a card.

Nymris, Oona's Trickster

Flash
Flying
Whenever you cast your first spell during each opponent's turn, look at the top two cards of your library. Put one of those cards into your hand and the other into your graveyard.

Morphic Pool

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Vivid Marsh

Vivid Marsh enters tapped with two charge counters on it.
{T}: Add {B}.
{T}, Remove a charge counter from Vivid Marsh: Add one mana of any color.

Plagiarize

Until end of turn, if target player would draw a card, instead that player skips that draw and you draw 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.

Startling Development

Until end of turn, target creature becomes a blue Serpent with base power and toughness 4/4.
Cycling {1} ({1}, Discard this card: Draw a card.)

Keep Safe

Counter target spell that targets a permanent you control.
Draw a card.

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Oona's Grace

Target player draws a card.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Call to Heel

Return target creature to its owner's hand. Its controller draws a card.

Rewind

Counter target spell. Untap up to four lands.

Dream Fracture

Counter target spell. Its controller draws a card.
Draw a card.

Bone to Ash

Counter target creature spell.
Draw a card.

Command Tower

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

Think Twice

Draw a card.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Crippling Chill

Tap target creature. It doesn't untap during its controller's next untap step.
Draw a card.

Squelch

Counter target activated ability. (Mana abilities can't be targeted.)
Draw a card.

Quasiduplicate

Create a token that's a copy of target creature you control.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Succumb to Temptation

Shark Typhoon

Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's mana value.
Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.)
When you cycle Shark Typhoon, create an X/X blue Shark creature token with flying.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Unwind

Counter target noncreature spell. Untap up to three lands.

Omen of the Sea

Flash (You may cast this spell any time you could cast an instant.)
When Omen of the Sea enters, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Swamp

Faerie Tauntings

Whenever you cast a spell during an opponent's turn, you may have each opponent lose 1 life.

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

Visions of Beyond

Draw a card. If a graveyard has twenty or more cards in it, draw three cards instead.

Dark Dabbling

Regenerate target creature. Draw a card. (The next time the creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, also regenerate each other creature you control.

Stinging Lionfish

Whenever you cast your first spell during each opponent's turn, you may tap or untap target nonland permanent.

Leadership Vacuum

Target player returns each commander they control from the battlefield to the command zone.
Draw a card.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sever the Bloodline

Exile target creature and all other creatures with the same name as that creature.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Voracious Reader

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Curious Homunculus

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.
At the beginning of your upkeep, if there are three or more instant and/or sorcery cards in your graveyard, transform Curious Homunculus.

Curious Homunculus // Voracious Reader

Obsessive Search

Draw a card.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Thirst for Knowledge

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

Illusionist's Gambit

Cast this spell only during the declare blockers step on an opponent's turn.
Remove all attacking creatures from combat and untap them. After this phase, there is an additional combat phase. Each of those creatures attacks that combat if able. They can't attack you or planeswalkers you control that combat.

Jwar Isle Refuge

Jwar Isle Refuge enters tapped.
When Jwar Isle Refuge enters, you gain 1 life.
{T}: Add {U} or {B}.

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Eyes of the Watcher

Whenever you cast an instant or sorcery spell, you may pay {1}. If you do, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Underground River

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

Decoy Gambit

For each opponent, choose up to one target creature that player controls, then return that creature to its owner's hand unless its controller has you draw a card.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Whelming Wave

Return all creatures to their owners' hands except for Krakens, Leviathans, Octopuses, and Serpents.

Frantic Search

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

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Arcane Signet

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

Island

God-Eternal Kefnet

Flying
You may reveal the first card you draw each turn as you draw it. Whenever you reveal an instant or sorcery card this way, copy that card and you may cast the copy. That copy costs {2} less to cast.
When God-Eternal Kefnet dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Primal Wellspring

(Transforms from Primal Amulet.)
{T}: Add one mana of any color. When that mana is spent to cast an instant or sorcery spell, copy that spell and you may choose new targets for the copy.

Primal Amulet

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, put a charge counter on Primal Amulet. Then if there are four or more charge counters on it, you may remove those counters and transform it.

Primal Amulet // Primal Wellspring

Voidmage Husher

Flash (You may cast this spell any time you could cast an instant.)
When Voidmage Husher enters, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

Dreamspoiler Witches

Flying
Whenever you cast a spell during an opponent's turn, you may have target creature get -1/-1 until end of turn.

Malakir Mire

Malakir Mire enters tapped.
{T}: Add {B}.

Malakir Rebirth

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Rebirth // Malakir Mire

Abnormal Endurance

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."

Thought Vessel

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Murkwater Pathway

Clearwater Pathway

Clearwater Pathway // Murkwater Pathway

Without Weakness

Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it. If its toughness is 0 or less, it's still put into its owner's graveyard.)
Cycling {2} ({2}, Discard this card: Draw a card.)

Hero's Downfall

Glacial Grasp

Tap target creature. Its controller mills two cards. That creature doesn't untap during its controller's next untap step. (They put the top two cards of their library into their graveyard.)
Draw a card.

Gravepurge

Jace's Sanctum

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, scry 1.

Ominous Seas

Whenever you draw a card, put a foreshadow counter on Ominous Seas.
Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Niblis of Frost

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Charcoal Diamond

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

Jace's Scrutiny

Target creature gets -4/-0 until end of turn.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")