Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Thought Monitor enters, draw two cards.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Kindred Discovery

As Kindred Discovery enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Rivendell

Rivendell enters tapped unless you control a legendary creature.
{T}: Add {U}.
{1}{U}, {T}: Scry 2. Activate only if you control a legendary creature.

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Thassa, God of the Sea

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.

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.

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Pongify

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

Ponder

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

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Curiosity Crafter

Flying
You have no maximum hand size.
Whenever a creature token you control deals combat damage to a player, draw a card.

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.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

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}.

Archmage Emeritus

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

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.

Negate

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Teferi, Temporal Archmage

+1: 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.
−1: Untap up to four target permanents.
−10: You get an emblem with "You may activate loyalty abilities of planeswalkers you control on any player's turn any time you could cast an instant."
Teferi, Temporal Archmage can be your commander.

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.")

Brainstorm

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

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Sapphire Medallion

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

Windfall

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

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, Ledger Shredder connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

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.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Rhystic Study

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

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Tezzeret, Betrayer of Flesh

The first activated ability of an artifact you activate each turn costs {2} less to activate.
+1: Draw two cards. Then discard two cards unless you discard an artifact card.
−2: Target artifact becomes an artifact creature. If it isn't a Vehicle, it has base power and toughness 4/4.
−6: You get an emblem with "Whenever an artifact you control becomes tapped, draw a card."

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.

Tribute Mage

When Tribute Mage enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Tezzeret the Seeker

+1: Untap up to two target artifacts.
−X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.
−5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

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.

Folio of Fancies

Players have no maximum hand size.
{X}{X}, {T}: Each player draws X cards.
{2}{U}, {T}: Each opponent mills cards equal to the number of cards in their hand.

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

Mechanized Production

Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Curiosity

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

Saw It Coming

Counter target spell.
Foretell {1}{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.)

Teferi's Veil

Whenever a creature you control attacks, it phases out at end of combat. (While it's phased out, it's treated as though it doesn't exist. It phases in before you untap during your next untap step.)

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.

High Tide

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

Solve the Equation

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

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.)

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Preordain

Scry 2, then draw a card. (To 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.)

Mystical Tutor

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

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

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

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.")

Retreat to Coralhelm

Landfall — Whenever a land you control enters, choose one —
• You may tap or untap target creature.
• Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Fabricate

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

Metallurgic Summonings

Whenever you cast an instant or sorcery spell, create an X/X colorless Construct artifact creature token, where X is that spell's mana value.
{3}{U}{U}, Exile Metallurgic Summonings: Return all instant and sorcery cards from your graveyard to your hand. Activate only if you control six or more artifacts.

Crystal Shard

{3}, {T} or {U}, {T}: Return target creature to its owner's hand unless its controller pays {1}.

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.

Tolaria West

Tolaria West enters tapped.
{T}: Add {U}.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with mana value 0, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Fierce Guardianship

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

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Frantic Search

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

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.

Cumber Stone

Creatures your opponents control get -1/-0.

Propaganda

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

Counterspell

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

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.