Arcane Melee

Instant and sorcery spells cost {2} less to cast.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Thought Vessel

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

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Flash Counter

Portent

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.
Draw a card at the beginning of the next turn's upkeep.

Thryx, the Sudden Storm

Flash
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Negate

Treasure Trove

Dissipate

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Kefnet's Monument

Blue creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Whelming Wave

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

Ancestral Memories

Look at the top seven cards of your library. Put two of them into your hand and the rest into your graveyard.

Soothsaying

{3}{U}{U}: Shuffle your library.
{X}: Look at the top X cards of your library, then put them back in any order.

Rewind

Counter target spell. Untap up to four lands.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

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.)

Mana Maze

Players can't cast spells that share a color with the spell most recently cast this turn.

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Thwart

You may return three Islands you control to their owner's hand rather than pay this spell's mana cost.
Counter target spell.

Quicksilver Fountain

At the beginning of each player's upkeep, that player puts a flood counter on target non-Island land they control of their choice. That land is an Island for as long as it has a flood counter on it.
At the beginning of each end step, if all lands on the battlefield are Islands, remove all flood counters from them.

Evacuation

Return all creatures to their owners' hands.

Foil

You may discard an Island card and another card rather than pay this spell's mana cost.
Counter target spell.

Merrow Harbinger

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
When Merrow Harbinger enters the battlefield, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

Paradigm Shift

Exile all cards from your library. Then shuffle your graveyard into your library.

Counterspell

Crawlspace

No more than two creatures can attack you each combat.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Leveler

When Leveler enters the battlefield, exile all cards from your library.

Rhystic Scrying

Draw three cards. Then if any player pays {2}, discard three cards.

Seahunter

{3}, {T}: Search your library for a Merfolk permanent card, put it onto the battlefield, then shuffle.

Wavebreak Hippocamp

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

Tidings

Concentrate

Isochron Scepter

Imprint — When Isochron Scepter enters the battlefield, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Gush

You may return two Islands you control to their owner's hand rather than pay this spell's mana cost.
Draw two cards.

Opportunity

Dismiss

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Academy Loremaster

At the beginning of each player's draw step, that player may draw an additional card. If they do, spells they cast this turn cost {2} more to cast.

Asinine Antics

You may cast Asinine Antics as though it had flash if you pay {2} more to cast it.
For each creature your opponents control, create a Cursed Role token attached to that creature. (If you control another Role on it, put that one into the graveyard. Enchanted creature is 1/1.)

Fierce Guardianship

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

Scourge of Fleets

When Scourge of Fleets enters the battlefield, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Turn Aside

Counter target spell that targets a permanent you control.

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Sleight of Hand

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Vedalken Orrery

You may cast spells as though they had flash.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Counterbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card.

Dream Cache

Draw three cards, then put two cards from your hand both on top of your library or both on the bottom of your library.

Sift

Mystic Confluence

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.

Meditate

Draw four cards. You skip your next turn.

Reliquary Tower

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

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.

Draining Whelk

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

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Island

Marit Lage's Slumber

Whenever Marit Lage's Slumber or another snow permanent enters the battlefield under your control, scry 1.
At the beginning of your upkeep, if you control ten or more snow permanents, sacrifice Marit Lage's Slumber. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

Castle Vantress

Castle Vantress enters the battlefield tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

The Reality Chip

You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Mindsplice Apparatus

Flash
At the beginning of your upkeep, put an oil counter on Mindsplice Apparatus.
Instant and sorcery spells you cast cost {1} less to cast for each oil counter on Mindsplice Apparatus.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Scroll Rack

{1}, {T}: Exile any number of cards from your hand face down. Put that many cards from the top of your library into your hand. Then look at the exiled cards and put them on top of your library in any order.

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.

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Anvil of Bogardan

Players have no maximum hand size.
At the beginning of each player's draw step, that player draws an additional card, then discards a card.

Keep Safe

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

Brainstorm

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

Fatespinner

At the beginning of each opponent's upkeep, that player chooses draw step, main phase, or combat phase. The player skips each instance of the chosen step or phase this turn.

Arcane Laboratory

Each player can't cast more than one spell each turn.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Brilliant Plan

Thought Lash

Cumulative upkeep—Exile the top card of your library. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When a player doesn't pay Thought Lash's cumulative upkeep, that player exiles all cards from their library.
Exile the top card of your library: Prevent the next 1 damage that would be dealt to you this turn.

Aetherspouts

For each attacking creature, its owner puts it on the top or bottom of their library.