Kefnet the Mindful

Flying, indestructible
Kefnet the Mindful 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.

Trade Routes

{1}: Return target land you control to its owner's hand.
{1}, Discard a land card: Draw a card.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Crumbling Vestige

Crumbling Vestige enters tapped.
When Crumbling Vestige enters, add one mana of any color.
{T}: Add {C}. ({C} represents colorless mana.)

Reliquary Tower

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

Blue Sun's Zenith

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

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Tiller Engine

Whenever a land you control enters tapped, choose one —
• Untap that land.
• Tap target nonland permanent an opponent controls.

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.)

Island

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control Roil Elemental.

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.)

Thwart

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

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Flow of Ideas

Foil

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

Whir of Invention

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Halimar Depths

Halimar Depths enters tapped.
When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Brainstorm

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

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Frantic Search

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

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Oboro Breezecaller

Flying
{2}, Return a land you control to its owner's hand: Untap target land.

Mana Breach

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

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.

Soratami Cloudskater

Flying
{2}, Return a land you control to its owner's hand: Draw a card, then discard a card.

Uyo, Silent Prophet

Flying
{2}, Return two lands you control to their owner's hand: Copy target instant or sorcery spell. You may choose new targets for the copy.

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Rewind

Counter target spell. Untap up to four lands.

Soratami Seer

Flying
{4}, Return two lands you control to their owner's hand: Discard all the cards in your hand, then draw that many cards.

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.)

Amulet of Vigor

Whenever a permanent you control enters tapped, untap it.

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.")

Thought Vessel

Ponder

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

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.

Rapid Hybridization

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

Unwind

Counter target noncreature spell. Untap up to three lands.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

High Tide

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

Spectral Deluge

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.
Foretell {1}{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.)

Gush

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

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Arcane Signet

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

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.

Sol Ring

Dizzy Spell

Target creature gets -3/-0 until end of turn.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Pongify

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

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Patron of the Moon

Moonfolk offering (You may cast this spell any time you could cast an instant by sacrificing a Moonfolk and paying the difference in mana costs between this and the sacrificed Moonfolk. Mana cost includes color.)
Flying
{1}: Put up to two land cards from your hand onto the battlefield tapped.

Sapphire Medallion

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

Flooded Shoreline

{U}{U}, Return two Islands you control to their owner's hand: Return target creature to its owner's hand.

Scaretiller

Whenever Scaretiller becomes tapped, choose one —
• You may put a land card from your hand onto the battlefield tapped.
• Return target land card from your graveyard to the battlefield tapped.

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.

Counterspell

Ensnare

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

Sunscorched Desert

When Sunscorched Desert enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Walking Atlas

{T}: You may put a land card from your hand onto the battlefield.

Soratami Mirror-Mage

Flying
{3}, Return three lands you control to their owner's hand: Return target creature to its owner's hand.

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.

Soratami Savant

Flying
{3}, Return a land you control to its owner's hand: Counter target spell unless its controller pays {3}.

Meloku the Clouded Mirror

Flying
{1}, Return a land you control to its owner's hand: Create a 1/1 blue Illusion creature token with flying.

Jeweled Lotus

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

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.

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.)

Tragic Lesson

Draw two cards. Then discard a card unless you return a land you control to its owner's hand.

Soratami Rainshaper

Flying
{3}, Return a land you control to its owner's hand: Target creature you control gains shroud until end of turn. (It can't be the target of spells or abilities.)

Thawing Glaciers

Thawing Glaciers enters tapped.
{1}, {T}: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Return Thawing Glaciers to its owner's hand at the beginning of the next cleanup step.

Gauntlet of Power

As Gauntlet of Power enters, choose a color.
Creatures of the chosen color get +1/+1.
Whenever a basic land is tapped for mana of the chosen color, its controller adds an additional one mana of that color.

Floodbringer

Flying
{2}, Return a land you control to its owner's hand: Tap target land.

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.)

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.