Thought Vessel

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

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Disallow

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

Jin-Gitaxias, Core Augur

Flash
At the beginning of your end step, draw seven cards.
Each opponent's maximum hand size is reduced by seven.

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.

Merchant Scroll

Search your library for a blue instant card, reveal that card, put it into your hand, then shuffle.

Tale's End

Counter target activated ability, triggered ability, or legendary spell.

Solve the Equation

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

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.

Reverse the Polarity

Choose one —
• Counter all other spells.
• Switch each creature's power and toughness until end of turn.
• Creatures can't be blocked this turn.

Arcane Signet

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

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Sol Ring

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.

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.

Sky Diamond

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Back to Basics

Nonbasic lands don't untap during their controllers' untap steps.

Dramatic Reversal

Untap all nonland permanents you control.

Unwind

Counter target noncreature spell. Untap up to three lands.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Enter the Infinite

Draw cards equal to the number of cards in your library, then put a card from your hand on top of your library. You have no maximum hand size until your next turn.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Negate

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.

Mocking Sprite

Flying
Instant and sorcery spells you cast cost {1} less to cast.

Archmage's Charm

Choose one —
• Counter target spell.
• Target player draws two cards.
• Gain control of target nonland permanent with mana value 1 or less.

Rewind

Counter target spell. Untap up to four lands.

Bane's Contingency

Counter target spell. If that spell targets a commander you control, instead counter that spell, scry 2, then draw a card.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Naiad of Hidden Coves

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

Ertai's Scorn

This spell costs {U} less to cast if an opponent cast two or more spells this turn.
Counter target spell.

Time Warp

Target player takes an extra turn after this one.

Jin-Gitaxias, Progress Tyrant

Whenever you cast an artifact, instant, or sorcery spell, copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.)
Whenever an opponent casts an artifact, instant, or sorcery spell, counter that spell. This ability triggers only once each turn.

Thassa's Oracle

When Thassa's Oracle enters, 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.)

Extraplanar Lens

Imprint — When Extraplanar Lens enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Windfall

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

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.

Out of Air

This spell costs {2} less to cast if it targets a creature spell.
Counter target spell.

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Snap

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

Mind Stone

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

Echo of Eons

Each player shuffles their hand and graveyard into their library, then draws seven cards.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Haughty Djinn

Flying
Haughty Djinn's power is equal to the number of instant and sorcery cards in your graveyard.
Instant and sorcery spells you cast cost {1} less to cast.

Mystic Remora

Cumulative upkeep {1} (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.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

You Find the Villains' Lair

Choose one —
• Foil Their Scheme — Counter target spell.
• Learn Their Secrets — Draw two cards, then discard two cards.

Dissipate

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

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

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.)

Misleading Signpost

Flash
When Misleading Signpost 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.)
{T}: Add {U}.

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Counterspell

Essence Scatter

Guile

Guile can't be blocked except by three or more creatures.
If a spell or ability you control would counter a spell, instead exile that spell and you may play that card without paying its mana cost.
When Guile is put into a graveyard from anywhere, shuffle it into its owner's library.

Leveler

When Leveler enters, exile all cards from your library.

Nexus of Fate

Take an extra turn after this one.
If Nexus of Fate would be put into a graveyard from anywhere, reveal Nexus of Fate and shuffle it into its owner's library instead.

Benevolent Geist

Flying
Noncreature spells you control can't be countered.
If Benevolent Geist would be put into a graveyard from anywhere, exile it instead.

Malevolent Hermit

{U}, Sacrifice Malevolent Hermit: Counter target noncreature spell unless its controller pays {3}.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Malevolent Hermit // Benevolent Geist

Swan Song

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

Isochron Scepter

Imprint — When Isochron Scepter enters, 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.

Mana Leak

Counter target spell unless its controller pays {3}.

Sapphire Medallion

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

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

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.)

Reliquary Tower

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Consecrated Sphinx

Flying
Whenever an opponent draws a card, you may draw two cards.

Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Wash Away

Cleave {1}{U}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Counter target spell [that wasn't cast from its owner's hand].