Stinging Lionfish

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

Torrential Gearhulk

Flash
When Torrential Gearhulk enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Reset

Cast this spell only during an opponent's turn after their upkeep step.
Untap all lands you control.

Blood Crypt

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

Bloodstained Mire

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

Command Tower

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

Omen of the Sea

Flash
When Omen of the Sea enters, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: Scry 2.

Mistbind Clique

Flash
Flying
Champion a Faerie (When this enters, sacrifice it unless you exile another Faerie you control. When this leaves the battlefield, that card returns to the battlefield.)
When a Faerie is championed with Mistbind Clique, tap all lands target player controls.

Faerie Harbinger

Flash
Flying
When Faerie Harbinger enters, you may search your library for a Faerie card, reveal it, then shuffle and put that card on top.

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Eel Umbra

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +1/+1.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

As Foretold

At the beginning of your upkeep, put a time counter on As Foretold.
Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less, where X is the number of time counters on As Foretold.

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Palinchron

Flying
When Palinchron enters, untap up to seven lands.
{2}{U}{U}: Return Palinchron to its owner's hand.

Temporal Mastery

Take an extra turn after this one. Exile Temporal Mastery.
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.)

Petty Theft

Return target nonland permanent an opponent controls to its owner's hand.

Brazen Borrower

Flash
Flying
Brazen Borrower can block only creatures with flying.

Brazen Borrower // Petty Theft

Watery Grave

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

Runeflare Trap

If an opponent drew three or more cards this turn, you may pay {R} rather than pay this spell's mana cost.
Runeflare Trap deals damage to target player equal to the number of cards in that player's hand.

Mad Ratter

Whenever you draw your second card each turn, create two 1/1 black Rat creature tokens.

Badlands

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Luxury Suite

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Faerie Vandal

Flash
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Faerie Vandal.

Submerge

If an opponent controls a Forest and you control an Island, you may cast this spell without paying its mana cost.
Put target creature on top of its owner's library.

Whiplash Trap

If an opponent had two or more creatures enter the battlefield under their control this turn, you may pay {U} rather than pay this spell's mana cost.
Return two target creatures to their owners' hands.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Ophidian Eye

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Draining Whelk

Flash
Flying
When Draining Whelk enters, counter target spell. Put X +1/+1 counters on Draining Whelk, where X is that spell's mana value.

Mulldrifter

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

Brainstorm

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

Ancient Stone Idol

Flash
This spell costs {1} less to cast for each attacking creature.
Trample
When Ancient Stone Idol dies, create a 6/12 colorless Construct artifact creature token with trample.

Vanishment

Put target nonland permanent on top of its owner's library.
Miracle {U} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Consuming Vapors

Target player sacrifices a creature. You gain life equal to that creature's toughness.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Portal Mage

Flash
When Portal Mage enters during the declare attackers step, you may reselect which player or permanent target attacking creature is attacking. (It can't attack its controller or their permanents.)

Dictate of Erebos

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

Spellstutter Sprite

Flash
Flying
When Spellstutter Sprite enters, counter target spell with mana value X or less, where X is the number of Faeries you control.

Shriekmaw

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

Polluted Delta

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

Faerie Tauntings

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

Arc Blade

Arc Blade deals 2 damage to any target. Exile Arc Blade with three time counters on it.
Suspend 3—{2}{R} (Rather than cast this card from your hand, you may pay {2}{R} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Great Whale

When Great Whale enters, untap up to seven lands.

Underground Sea

Mizzium Meddler

Flash (You may cast this spell any time you could cast an instant.)
When Mizzium Meddler enters, you may change a target of target spell or ability to Mizzium Meddler.

Quickling

Flash (You may cast this spell any time you could cast an instant.)
Flying
When Quickling enters, sacrifice it unless you return another creature you control to its owner's hand.

Irencrag Pyromancer

Whenever you draw your second card each turn, Irencrag Pyromancer deals 3 damage to any target.

Thought Sponge

Flash
Thought Sponge enters with a number of +1/+1 counters on it equal to the greatest number of cards an opponent has drawn this turn.
When Thought Sponge dies, draw cards equal to its power.

Staggershock

Staggershock deals 2 damage to any target.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Vial Smasher the Fierce

Whenever you cast your first spell each turn, choose an opponent at random. Vial Smasher the Fierce deals damage equal to that spell's mana value to that player or a planeswalker that player controls.
Partner (You can have two commanders if both have partner.)

Improbable Alliance

Whenever you draw your second card each turn, create a 1/1 blue Faerie creature token with flying.
{4}{U}{R}: Draw a card, then discard a card.

Frantic Search

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

Spelljack

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may play it without paying its mana cost for as long as it remains exiled. (If it has X in its mana cost, X is 0.)

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Deep-Sea Kraken

Deep-Sea Kraken can't be blocked.
Suspend 9—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever an opponent casts a spell, if Deep-Sea Kraken is suspended, remove a time counter from it.

Alexi's Cloak

Flash
Enchant creature
Enchanted creature has shroud. (It can't be the target of spells or abilities.)

Curtains' Call

Undaunted (This spell costs {1} less to cast for each opponent.)
Destroy two target creatures.

Ingot Chewer

When Ingot Chewer enters, destroy target artifact.
Evoke {R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Scalding Tarn

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

Exotic Orchard

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

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Island

Swamp

Snap

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

Merfolk Trickster

Flash
When Merfolk Trickster enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Needlebite Trap

If an opponent gained life this turn, you may pay {B} rather than pay this spell's mana cost.
Target player loses 5 life and you gain 5 life.

Peregrine Drake

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

Steam Vents

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

Reality Strobe

Return target permanent to its owner's hand. Exile Reality Strobe with three time counters on it.
Suspend 3—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Mischievous Chimera

Flying
Whenever you cast your first spell during each opponent's turn, Mischievous Chimera deals 1 damage to each opponent. Scry 1.

Riftwing Cloudskate

Flying
When Riftwing Cloudskate enters, return target permanent to its owner's hand.
Suspend 3—{1}{U} (Rather than cast this card from your hand, you may pay {1}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Mountain

Wavebreak Hippocamp

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

Rewind

Counter target spell. Untap up to four lands.

Morphic Pool

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

Treachery

Enchant creature
When Treachery enters, untap up to five lands.
You control enchanted creature.

Ludevic, Necro-Alchemist

At the beginning of each player's end step, that player may draw a card if a player other than you lost life this turn.
Partner (You can have two commanders if both have partner.)

Misdirection

You may exile a blue card from your hand rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Stunt Double

Flash
You may have Stunt Double enter as a copy of any creature on the battlefield.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Volcanic Island

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 Brineborn Cutthroat.

Unwind

Counter target noncreature spell. Untap up to three lands.

Sentinel of the Pearl Trident

Flash
When Sentinel of the Pearl Trident enters, you may exile target historic permanent you control. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step. (Artifacts, legendaries, and Sagas are historic.)