Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Contentious Plan

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Vivisurgeon's Insight

Draw three cards. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Relearn

Return target instant or sorcery card from your graveyard to your hand.

Rescind

Return target permanent to its owner's hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

Disallow

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

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Guildpact Informant

Flying
Whenever Guildpact Informant deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Foil

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

Reject Imperfection

Counter target spell. If that spell's mana value was 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.

Drafna, Founder of Lat-Nam

{1}{U}: Return target artifact you control to its owner's hand.
{3}, {T}: Copy target artifact spell you control. (The copy becomes a token.)

Foundry Inspector

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

Worn Powerstone

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

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

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.

Teferi, Master of Time

You may activate loyalty abilities of Teferi, Master of Time on any player's turn any time you could cast an instant.
+1: Draw a card, then discard a card.
−3: Target creature you don't control phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
−10: Take two extra turns after this one.

Teferi, Temporal Pilgrim

Whenever you draw a card, put a loyalty counter on Teferi, Temporal Pilgrim.
0: Draw a card.
−2: Create a 2/2 blue Spirit creature token with vigilance and "Whenever you draw a card, put a +1/+1 counter on this creature."
−12: Target opponent chooses a permanent they control and returns it to its owner's hand. Then they shuffle each nonland permanent they control into its owner's library.

Sudden Substitution

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Exchange control of target noncreature spell and target creature. Then the spell's controller may choose new targets for it.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Sol Ring

Cryptic Command

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

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.

Gush

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

Serum Snare

Return target nonland permanent to its owner's hand. If that permanent had mana value 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Unwind

Counter target noncreature spell. Untap up to three lands.

Capsize

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Return target permanent to its owner's hand.

Rhystic Study

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

Steady Progress

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.

Gilded Lotus

Repulse

Return target creature to its owner's hand.
Draw a card.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Astral Cornucopia

Astral Cornucopia enters with X charge counters on it.
{T}: Choose a color. Add one mana of that color for each charge counter on Astral Cornucopia.

Thwart

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

Snapback

You may exile a blue card from your hand rather than pay this spell's mana cost.
Return target creature to its owner's hand.

Mental Misstep

({U/P} can be paid with either {U} or 2 life.)
Counter target spell with mana value 1.

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.)

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Long-Term Plans

Search your library for a card, then shuffle and put that card third from the top.

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

High Tide

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

Dream Halls

Rather than pay the mana cost for a spell, its controller may discard a card that shares a color with that spell.

Thran Dynamo

Mesmerizing Dose

Enchant creature
When Mesmerizing Dose enters, tap enchanted creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Enchanted creature doesn't untap during its controller's untap step.

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.

Dramatic Reversal

Untap all nonland permanents you control.

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Commandeer

You may exile two blue cards from your hand rather than pay this spell's mana cost.
Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters under your control.)

Turnabout

Choose artifact, creature, or land. Tap all untapped permanents of the chosen type target player controls, or untap all tapped permanents of that type that player controls.

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.

Vedalken Orrery

You may cast spells as though they had flash.

Wipe Away

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Return target permanent to its owner's hand.

Thoughtcast

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Draw two cards.

Mind's Desire

Shuffle your library. Then exile the top card of your library. Until end of turn, you may play that card without paying its mana cost.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Solve the Equation

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

Fellwar Stone

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

Rewind

Counter target spell. Untap up to four lands.

Helm of Awakening

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Temporal Fissure

Return target permanent to its owner's hand.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Irenicus's Vile Duplication

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Alrund's Epiphany

Create two 1/1 blue Bird creature tokens with flying. Take an extra turn after this one. Exile Alrund's Epiphany.
Foretell {4}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

The Great Synthesis

(As this Saga enters and after your draw step, add a lore counter.)
I — Draw cards equal to the number of cards in your hand. You have no maximum hand size for as long as you control The Great Synthesis.
II — Return all non-Phyrexian creatures to their owners' hands.
III — You may cast any number of spells from your hand without paying their mana costs. Exile The Great Synthesis, then return it to the battlefield (front face up).

Jin-Gitaxias

Ward {2}
Whenever you cast a noncreature spell with mana value 3 or greater, draw a card.
{3}{U}: Exile Jin-Gitaxias, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery and only if you have seven or more cards in hand.

Jin-Gitaxias // The Great Synthesis

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Pull from Tomorrow

Press the Enemy

Return target spell or nonland permanent an opponent controls to its owner's hand. You may cast an instant or sorcery spell with equal or lesser mana value from your hand without paying its mana cost.

Snap

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

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Magistrate's Scepter

{4}, {T}: Put a charge counter on Magistrate's Scepter.
{T}, Remove three charge counters from Magistrate's Scepter: Take an extra turn after this one.

Arcane Signet

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

Swarm Intelligence

Whenever you cast an instant or sorcery spell, you may copy that spell. You may choose new targets for the copy.

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Forbid

Buyback—Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Counter target spell.

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Ichormoon Gauntlet

Planeswalkers you control have "[0]: Proliferate" and "[−12]: Take an extra turn after this one."
Whenever you cast a noncreature spell, choose a counter on target permanent. Put an additional counter of that kind on that permanent.

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Walk the Aeons

Buyback—Sacrifice three Islands. (You may sacrifice three Islands in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Target player takes an extra turn after this one.