Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Whispering Madness

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Empyrial Armor

Enchant creature
Enchanted creature gets +1/+1 for each card in your hand.

Traumatize

Target player mills half their library, rounded down.

Propaganda

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

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.

Gadwick, the Wizened

When Gadwick, the Wizened enters the battlefield, draw X cards.
Whenever you cast a blue spell, tap target nonland permanent an opponent controls.

Coalition Relic

{T}: Add one mana of any color.
{T}: Put a charge counter on Coalition Relic.
At the beginning of your precombat main phase, remove all charge counters from Coalition Relic. Add one mana of any color for each charge counter removed this way.

Illusionary Terrain

Cumulative upkeep {2} (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.)
As Illusionary Terrain enters the battlefield, choose two basic land types.
Basic lands of the first chosen type are the second chosen type.

Aboshan, Cephalid Emperor

Tap an untapped Octopus you control: Tap target permanent.
{U}{U}{U}: Tap all creatures without flying.

Pulse of the Grid

Draw two cards, then discard a card. Then if an opponent has more cards in hand than you, return Pulse of the Grid to its owner's hand.

Angelic Renewal

Whenever a creature is put into your graveyard from the battlefield, you may sacrifice Angelic Renewal. If you do, return that card to the battlefield.

Windfall

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

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Fierce Guardianship

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

Court of Cunning

When Court of Cunning enters the battlefield, 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.)

Thieves' Tools

When Thieves' Tools enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equipped creature can't be blocked as long as its power is 3 or less.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Teferi's Tutelage

When Teferi's Tutelage enters the battlefield, draw a card, then discard a card.
Whenever you draw a card, target opponent mills two cards. (They put the top two cards of their library into their graveyard.)

Island Sanctuary

If you would draw a card during your draw step, instead you may skip that draw. If you do, until your next turn, you can't be attacked except by creatures with flying and/or islandwalk.

The Trickster-God's Heist

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — You may exchange control of two target creatures.
II — You may exchange control of two target nonbasic, noncreature permanents that share a card type.
III — Target player loses 3 life and you gain 3 life.

Estrid's Invocation

You may have Estrid's Invocation enter the battlefield as a copy of an enchantment you control, except it has "At the beginning of your upkeep, you may exile this enchantment. If you do, return it to the battlefield under its owner's control."

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Attunement

Return Attunement to its owner's hand: Draw three cards, then discard four cards.

Dark Sphere

{T}, Sacrifice Dark Sphere: The next time a source of your choice would deal damage to you this turn, prevent half that damage, rounded down.

Cunning Evasion

Whenever a creature you control becomes blocked, you may return it to its owner's hand.

Toothy, Imaginary Friend

Partner with Pir, Imaginative Rascal (When this creature enters the battlefield, 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.

Stormtide Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
All lands are Islands in addition to their other types.
Creatures without flying or islandwalk can't attack.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Ghostly Prison

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

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.

Grand Coliseum

Grand Coliseum enters the battlefield tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Grand Coliseum deals 1 damage to you.

Alseid of Life's Bounty

Lifelink
{1}, Sacrifice Alseid of Life's Bounty: Target creature or enchantment you control gains protection from the color of your choice until end of turn.

Weathered Wayfarer

{W}, {T}: Search your library for a land card, reveal it, put it into your hand, then shuffle. Activate only if an opponent controls more lands than you.

Rescind

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

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Seal of Cleansing

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

Karmic Justice

Whenever a spell or ability an opponent controls destroys a noncreature permanent you control, you may destroy target permanent that opponent controls.

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.)

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
Raffine's Tower enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Cover of Darkness

As Cover of Darkness enters the battlefield, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Commander's Sphere

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

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Mirrormade

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

Jace's Erasure

Whenever you draw a card, you may have target player mill a card.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Decanter of Endless Water

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

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Frantic Search

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

Queza, Augur of Agonies

Whenever you draw a card, target opponent loses 1 life and you gain 1 life.

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.)

Eaten by Piranhas

Flash
Enchant creature
Enchanted creature loses all abilities and is a black Skeleton creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Arcane Signet

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

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.

Deserted Beach

Deserted Beach enters the battlefield tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Aetherize

Return all attacking creatures to their owner's hand.

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.

Glasspool Shore

Glasspool Shore enters the battlefield tapped.
{T}: Add {U}.

Glasspool Mimic

You may have Glasspool Mimic enter the battlefield as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Mimic // Glasspool Shore

Forbidden Orchard

{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.

Lunar Force

When an opponent casts a spell, sacrifice Lunar Force and counter that spell.

Academy Ruins

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

Island

Standstill

When a player casts a spell, sacrifice Standstill. If you do, each of that player's opponents draws three cards.

Wall of Shards

Defender, flying
Cumulative upkeep—An opponent gains 1 life. (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.)

Deadly Designs

{2}: Put a plot counter on Deadly Designs. Any player may activate this ability.
When there are five or more plot counters on Deadly Designs, sacrifice it. If you do, destroy up to two target creatures.

Mana Breach

Whenever a player casts a spell, that player returns a land they control to its owner's hand.

Bitterblossom

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

Thought Vessel

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

Command Tower

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Sword of Once and Future

Equipped creature gets +2/+2 and has protection from blue and from black.
Whenever equipped creature deals combat damage to a player, surveil 2. Then you may cast an instant or sorcery spell with mana value 2 or less from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.
Equip {2}

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.

Recalibrate

Return target creature to its owner's hand. If you've discarded a card this turn, draw a card.

Psychic Corrosion

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

Floodgate

Defender (This creature can't attack.)
When Floodgate has flying, sacrifice it.
When Floodgate leaves the battlefield, it deals damage equal to half the number of Islands you control, rounded down, to each nonblue creature without flying.

Cephalid Constable

Whenever Cephalid Constable deals combat damage to a player, return up to that many target permanents that player controls to their owner's hand.

Platinum Angel

Flying
You can't lose the game and your opponents can't win the game.

Font of Return

{3}{B}, Sacrifice Font of Return: Return up to three target creature cards from your graveyard to your hand.

Energy Field

Prevent all damage that would be dealt to you by sources you don't control.
When a card is put into your graveyard from anywhere, sacrifice Energy Field.

Copy Enchantment

You may have Copy Enchantment enter the battlefield as a copy of any enchantment on the battlefield.

Sapphire Medallion

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

Cephalid Facetaker

Cephalid Facetaker can't be blocked.
At the beginning of combat on your turn, you may have Cephalid Facetaker become a copy of another target creature until end of turn, except it's 1/4 and has "This creature can't be blocked."

Ominous Seas

Whenever you draw a card, put a foreshadow counter on Ominous Seas.
Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Zur the Enchanter

Flying
Whenever Zur the Enchanter attacks, you may search your library for an enchantment card with mana value 3 or less, put it onto the battlefield, then shuffle.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Cowardice

Whenever a creature becomes the target of a spell or ability, return that creature to its owner's hand. (It won't be affected by the spell or ability.)

Viral Drake

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Obscura Confluence

Choose three. You may choose the same mode more than once.
• Until end of turn, target creature loses all abilities and has base power and toughness 1/1.
• Target creature connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)
• Target player returns a creature card from their graveyard to their hand.

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Tolarian Winds

Discard all the cards in your hand, then draw that many cards.

Prosperous Thief

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 one or more Ninja or Rogue creatures you control deal combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Brainstorm

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

Heliod, Sun-Crowned

Indestructible
As long as your devotion to white is less than five, Heliod isn't a creature.
Whenever you gain life, put a +1/+1 counter on target creature or enchantment you control.
{1}{W}: Another target creature gains lifelink until end of turn.

Scourge of Fleets

When Scourge of Fleets enters the battlefield, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.