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 this card, create an X/X blue Shark creature token with flying.

Reckless Scholar

{T}: Target player draws a card, then discards a card.

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

Archmage of Runes

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, draw a card.

Sapphire Medallion

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

Sol Ring

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

Syr Elenora, the Discerning

Syr Elenora's power is equal to the number of cards in your hand.
When Syr Elenora enters, draw a card.
Spells your opponents cast that target Syr Elenora cost {2} more to cast.

Decanter of Endless Water

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

Kelpie Guide

{T}: Untap another target permanent you control.
{T}: Tap target permanent. Activate only if you control eight or more lands.

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.

Thassa's Oracle

When this creature 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.)

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.

Court of Cunning

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, any number of target players each mill two cards. If you're the monarch, each of those players mills ten cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Isochron Scepter

Imprint — When this artifact 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.

Siren Stormtamer

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

Mystic Sanctuary

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

Negate

Strategic Planning

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

High Tide

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

Thought Vessel

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

Arcane Laboratory

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

Jace Beleren

+2: Each player draws a card.
−1: Target player draws a card.
−10: Target player mills twenty cards.

Consecrated Sphinx

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

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Frantic Search

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

Careful Study

Letter of Acceptance

{T}: Add one mana of any color.
{2}, {T}, Sacrifice this artifact: Draw a card.

Brainstorm

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

Minds Aglow

Join forces — Starting with you, each player may pay any amount of mana. Each player draws X cards, where X is the total amount of mana paid this way.

Overlord of the Floodpits

Impending 4—{1}{U}{U} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Flying
Whenever this permanent enters or attacks, draw two cards, then discard a card.

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.)

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser enters, return target spell or permanent to its owner's hand.

Seal of Removal

Sacrifice this enchantment: Return target creature to its owner's hand.

Treasure Cruise

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

Mordenkainen

+2: Draw two cards, then put a card from your hand on the bottom of your library.
−2: Create a blue Dog Illusion creature token with "This token's power and toughness are each equal to twice the number of cards in your hand."
−10: Exchange your hand and library, then shuffle. You get an emblem with "You have no maximum hand size."

Diplomatic Escort

{U}, {T}, Discard a card: Counter target spell or ability that targets a creature.

Fade Away

For each creature, its controller sacrifices a permanent of their choice unless they pay {1}.

Command Tower

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

Island

Fatestitcher

{T}: You may tap or untap another target permanent.
Unearth {U} ({U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Looter il-Kor

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever this creature deals damage to an opponent, draw a card, then discard a card.

Merchant Scroll

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

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

The Mindskinner

The Mindskinner can't be blocked.
If a source you control would deal damage to an opponent, prevent that damage and each opponent mills that many cards.

Flood of Recollection

Return target instant or sorcery card from your graveyard to your hand. Exile Flood of Recollection.

Gudul Lurker

This creature can't be blocked.
Megamorph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Mindbreak Trap

If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost.
Exile any number of target spells.

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Snow-Covered Wastes

Body of Knowledge

Body of Knowledge's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
Whenever this creature is dealt damage, draw that many cards.

Reset

Cast this spell only during an opponent's turn after their upkeep step.
Untap all lands you control.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Kefnet the Mindful

Flying, indestructible
Kefnet can't attack or block unless you have seven or more cards in hand.
{3}{U}: Draw a card, then you may return a land you control to its owner's hand.

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.

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Stifle

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

Strix Lookout

Flying, vigilance (Attacking doesn't cause this creature to tap.)
{1}{U}, {T}: Draw a card, then discard 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.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Winged Words

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

Thought Courier

Kitsa, Otterball Elite

Vigilance
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{T}: Draw a card, then discard a card.
{2}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. Activate only if Kitsa's power is 3 or greater.

Flash of Insight

Look at the top X cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.
Flashback—{1}{U}, Exile X blue cards from your graveyard. (You may cast this card from your graveyard for its flashback cost, then exile it. You can't exile Flash of Insight to pay for its own flashback cost.)

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.)

Mothdust Changeling

Changeling (This card is every creature type.)
Tap an untapped creature you control: This creature gains flying until end of turn.

Guardian of Tazeem

Flying
Landfall — Whenever a land you control enters, tap target creature an opponent controls. If that land is an Island, that creature doesn't untap during its controller's next untap step.

Octavia, Living Thesis

This spell costs {8} less to cast if you have eight or more instant and/or sorcery cards in your graveyard.
Ward {8}
Magecraft — Whenever you cast or copy an instant or sorcery spell, target creature has base power and toughness 8/8 until end of turn.

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.

Archaeomancer

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

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Riptide Laboratory

{T}: Add {C}.
{1}{U}, {T}: Return target Wizard you control to its owner's hand.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Pemmin's Aura

Enchant creature
{U}: Untap enchanted creature.
{U}: Enchanted creature gains flying until end of turn.
{U}: Enchanted creature gains shroud until end of turn. (It can't be the target of spells or abilities.)
{1}: Enchanted creature gets +1/-1 or -1/+1 until end of turn.

Tsabo's Web

When this artifact enters, draw a card.
Each land with an activated ability that isn't a mana ability doesn't untap during its controller's untap step.

Heraldic Banner

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Deepchannel Mentor

Blue creatures you control can't be blocked.

Cynette, Jelly Drover

When Cynette enters or dies, create a 1/1 blue Jellyfish creature token with flying.
Creatures you control with flying get +1/+1.

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.)

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.