Metropolis Sprite

Flying
{U}: Metropolis Sprite gets +1/-1 until end of turn.

Harrier Strix

Flying
When Harrier Strix enters, tap target permanent.
{2}{U}: Draw a card, then discard a card.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

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.)

Meeting of Minds

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Draw two cards.

Mnemonic Sphere

{1}{U}, Sacrifice Mnemonic Sphere: Draw two cards.
Channel — {U}, Discard Mnemonic Sphere: Draw a card.

Fae Flight

Flash
Enchant creature
When Fae Flight enters, enchanted creature gains hexproof until end of turn.
Enchanted creature gets +1/+0 and has flying.

Alora, Merry Thief

Whenever you attack, up to one target attacking creature can't be blocked this turn. Return that creature to its owner's hand at the beginning of the next end step.
Choose a Background (You can have a Background as a second commander.)

Swirling Torrent

Choose one or both —
• Put target creature on top of its owner's library.
• Return target creature to its owner's hand.

Disperse

Return target nonland permanent to its owner's hand.

Octoprophet

When Octoprophet enters, 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.)

Moment of Truth

Look at the top three cards of your library. Put one of those cards into your hand, one into your graveyard, and one on the bottom of your library.

Catlike Curiosity

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
If Catlike Curiosity would be put into a graveyard from anywhere, exile it instead.

Mischievous Catgeist

Whenever Mischievous Catgeist deals combat damage to a player, draw a card.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mischievous Catgeist // Catlike Curiosity

Storm Reading

Draw four cards, then discard two cards. (Then exile this card. You may cast the creature later from exile.)

Galvanic Giant

Whenever you cast a spell with mana value 5 or greater, tap target creature an opponent controls and put a stun counter on it.

Galvanic Giant // Storm Reading

Skitter Eel

{2}{U}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

Tamiyo's Immobilizer

Tamiyo's Immobilizer enters with four oil counters on it.
{T}, Remove an oil counter from Tamiyo's Immobilizer: Tap target artifact or creature.

Scour All Possibilities

Scry 2, then draw a card.
Flashback {4}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Freed from the Real

Enchant creature
{U}: Tap enchanted creature.
{U}: Untap enchanted creature.

Brainstorm

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

Cunning Geysermage

Kicker {2}{U} (You may pay an additional {2}{U} as you cast this spell.)
When Cunning Geysermage enters, if it was kicked, return up to one other target creature to its owner's hand.

Gray Harbor Merfolk

Gray Harbor Merfolk can't be blocked.
Gray Harbor Merfolk gets +2/+0 as long as you control a commander that's a creature or planeswalker.

Unexplained Disappearance

Return target creature to its owner's hand.
Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Deny the Divine

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

Unsubstantiate

Return target spell or creature to its owner's hand.

Mistway Spy

Flying
Disguise {1}{U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When Mistway Spy is turned face up, until end of turn, whenever a creature you control deals combat damage to a player, investigate.

Tempest Caller

When Tempest Caller enters, tap all creatures target opponent controls.

Neutralizing Blast

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.

Covert Technician

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Covert Technician deals combat damage to a player, you may put an artifact card with mana value less than or equal to that damage from your hand onto the battlefield.

Efficient Construction

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

Memory Drain

Smoke Shroud

Enchant creature
Enchanted creature gets +1/+1 and has flying.
When a Ninja you control enters, you may return Smoke Shroud from your graveyard to the battlefield attached to that creature.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Syphon Essence

Counter target creature or planeswalker spell. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Whisk Away

Put target attacking or blocking creature on top of its owner's library.

Convolute

Counter target spell unless its controller pays {4}.

Toothy, Imaginary Friend

Partner with Pir, Imaginative Rascal (When this creature enters, target player may put Pir into their hand from their library, then shuffle.)
Whenever you draw a card, put a +1/+1 counter on Toothy, Imaginary Friend.
When Toothy leaves the battlefield, draw a card for each +1/+1 counter on it.

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Timely Interference

Kicker {1}{R} (You may pay an additional {1}{R} as you cast this spell.)
Target creature gets -1/-0 until end of turn. If this spell was kicked, that creature blocks this turn if able.
Draw a card.

Rapid Hybridization

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

Lose Focus

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Counter target spell unless its controller pays {2}.

Mentor's Guidance

When you cast this spell, copy it if you control a planeswalker, Cleric, Druid, Shaman, Warlock, or Wizard.
Scry 1, then draw a card.

Unauthorized Exit

Return target nonland permanent to its owner's hand. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Sleep of the Dead

Tap target creature. It doesn't untap during its controller's next untap step.
Escape—{2}{U}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Archmage Emeritus

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

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Veiling Oddity

Suspend 4—{1}{U} (Rather than cast this card from your hand, you may pay {1}{U} and exile it with four 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.)
When the last time counter is removed from Veiling Oddity while it's exiled, creatures can't be blocked this turn.

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.

Divide by Zero

Return target spell or permanent with mana value 1 or greater to its owner's hand.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Archaeomender

When Archaeomender enters, return target artifact card from your graveyard to your hand.

Horizon Scholar

Flying
When Horizon Scholar enters, 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.)

Chemister's Insight

Draw two cards.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Sailor of Means

When Sailor of Means enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Aquatic Incursion

When Aquatic Incursion enters, create two 1/1 blue Merfolk creature tokens with hexproof. (They can't be the targets of spells or abilities your opponents control.)
{3}{U}: Target Merfolk can't be blocked this turn.

Choking Tethers

Tap up to four target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Choking Tethers, you may tap target creature.

Brinebarrow Intruder

Flash
When Brinebarrow Intruder enters, target creature an opponent controls gets -2/-0 until end of turn.

Witching Well

When Witching Well enters, 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.)
{3}{U}, Sacrifice Witching Well: Draw two cards.

Triton Shorestalker

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Burdened Aerialist

When Burdened Aerialist enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a token, Burdened Aerialist gains flying until end of turn.

Annul

Counter target artifact or enchantment spell.

Repulse

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

Deliberate

Esoteric Duplicator

Whenever you sacrifice Esoteric Duplicator or another artifact, you may pay {2}. If you do, at the beginning of the next end step, create a token that's a copy of that artifact.
{2}, Sacrifice Esoteric Duplicator: Draw a card.

Spellweaver Duo

Assist (Another player can pay up to {6} of this spell's cost.)
When Spellweaver Duo enters, you may return target tapped creature to its owner's hand.

Rona's Vortex

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Return target creature or planeswalker you don't control to its owner's hand. If this spell was kicked, put that permanent on the bottom of its owner's library instead.

Svyelun of Sea and Sky

Svyelun of Sea and Sky has indestructible as long as you control at least two other Merfolk.
Whenever Svyelun attacks, draw a card.
Other Merfolk you control have ward {1}. (Whenever another Merfolk you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Broodbirth Viper

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Broodbirth Viper deals combat damage to a player, you may draw a card.

Emperor Mihail II

You may look at the top card of your library any time.
You may cast Merfolk spells from the top of your library.
Whenever you cast a Merfolk spell, you may pay {1}. If you do, create a 1/1 blue Merfolk creature token.

Stratus Walk

Enchant creature
When Stratus Walk enters, draw a card.
Enchanted creature has flying. (It can't be blocked except by creatures with flying or reach.)
Enchanted creature can block only creatures with flying.

Entry Denied

Return target creature you don't control with mana value 3 or less to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Beluna's Gatekeeper

Beluna's Gatekeeper // Entry Denied

Switcheroo

Exchange control of two target creatures.

Steelclad Spirit

Defender
Whenever an enchantment you control enters, Steelclad Spirit can attack this turn as though it didn't have defender.

Clash of Wills

Counter target spell unless its controller pays {X}.

Nimbus Champion

Flying
Whenever Nimbus Champion attacks, you may return target creature to its owner's hand if that creature's power is less than or equal to the number of Warriors your team controls.

Reverse Engineer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Draw three cards.

Bone to Ash

Counter target creature spell.
Draw a card.

Phantasmal Dreadmaw

Trample
When Phantasmal Dreadmaw becomes the target of a spell or ability, sacrifice it.

Imoen, Mystic Trickster

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
At the beginning of your end step, if you have the initiative, draw a card. Draw another card if you've completed a dungeon.
Choose a Background (You can have a Background as a second commander.)

Harbor Serpent

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Harbor Serpent can't attack unless there are five or more Islands on the battlefield.

Inga Rune-Eyes

When Inga Rune-Eyes enters, scry 3.
When Inga Rune-Eyes dies, draw three cards if three or more creatures died this turn.

Waterfall Aerialist

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Malcolm, Alluring Scoundrel

Flash
Flying
Whenever Malcolm, Alluring Scoundrel deals combat damage to a player, put a chorus counter on it. Draw a card, then discard a card. If there are four or more chorus counters on Malcolm, you may cast the discarded card without paying its mana cost.

Gadwick's First Duel

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a Cursed Role token attached to up to one target creature. (If you control another Role on it, put that one into the graveyard. Enchanted creature is 1/1.)
II — Scry 2.
III — When you next cast an instant or sorcery spell with mana value 3 or less this turn, copy that spell. You may choose new targets for the copy.

Daring Saboteur

{2}{U}: Daring Saboteur can't be blocked this turn.
Whenever Daring Saboteur deals combat damage to a player, you may draw a card. If you do, discard a card.

Wind Strider

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Cancel

Relentless Skaabs

As an additional cost to cast this spell, exile a creature card from your graveyard.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Murmuring Phantasm

Shipwreck Sifters

When Shipwreck Sifters enters, draw a card, then discard a card.
Whenever you discard a Spirit card or a card with disturb, put a +1/+1 counter on Shipwreck Sifters.

Coral Trickster

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Coral Trickster is turned face up, you may tap or untap target permanent.

Aven Eternal

Flying
When Aven Eternal enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Wingfold Pteron

Wingfold Pteron enters with your choice of a flying counter or a hexproof counter on it. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Didn't Say Please

Counter target spell. Its controller mills three cards.

Man-o'-War

When Man-o'-War enters, return target creature to its owner's hand.

Glimpse the Cosmos

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.
As long as you control a Giant, you may cast Glimpse the Cosmos from your graveyard by paying {U} rather than paying its mana cost. If you cast Glimpse the Cosmos this way and it would be put into your graveyard, exile it instead.