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.)

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Floodbringer

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

Zhalfirin Void

When Zhalfirin Void enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {C}.

Quick Study

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.

Sapphire Medallion

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

Thran Dynamo

Stroke of Genius

Azami, Lady of Scrolls

Tap an untapped Wizard you control: Draw a card.

Blue Sun's Zenith

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

Trade Routes

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

Oboro Breezecaller

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

Sunder

Oboro, Palace in the Clouds

{T}: Add {U}.
{1}: Return Oboro, Palace in the Clouds to its owner's hand.

Expedition Map

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

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

High Tide

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

Rapid Hybridization

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

Flow of Ideas

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.

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}.

Capsize

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Return target permanent to its owner's hand.

The Omenkeel

Whenever a Vehicle you control deals combat damage to a player, that player exiles that many cards from the top of their library. You may play lands from among those cards for as long as they remain exiled.
Crew 1

Cosima, God of the Voyage

At the beginning of your upkeep, you may exile Cosima. If you do, it gains "Whenever a land you control enters, if Cosima is exiled, you may put a voyage counter on it. If you don't, return Cosima to the battlefield with X +1/+1 counters on it and draw X cards, where X is the number of voyage counters on it."

Cosima, God of the Voyage // The Omenkeel

Soratami Savant

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

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.)

Flow of Knowledge

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

Ensnare

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

Ghirapur Orrery

Each player may play an additional land on each of their turns.
At the beginning of each player's upkeep, if that player has no cards in hand, that player draws three cards.

Amulet of Vigor

Whenever a permanent you control enters tapped, untap it.

Tragic Lesson

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

Horn of Greed

Whenever a player plays a land, that player draws a card.

Reliquary Tower

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

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Seer's Sundial

Landfall — Whenever a land you control enters, you may pay {2}. If you do, draw a card.

Khalni Gem

When Khalni Gem enters, return two lands you control to their owner's hand.
{T}: Add two mana of any one color.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Maze of Ith

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

Deprive

As an additional cost to cast this spell, return a land you control to its owner's hand.
Counter target spell.

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

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.

Overburden

Whenever a player puts a nontoken creature onto the battlefield, that player returns a land they control to its owner's hand.

Rhystic Study

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

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.

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.

Sunscorched Desert

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

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.

Replication Specialist

Flying
Whenever a nontoken artifact you control enters, you may pay {1}{U}. If you do, create a token that's a copy of that artifact.

Tiller Engine

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

Ghost Town

{T}: Add {C}.
{0}: Return Ghost Town to its owner's hand. Activate only if it's not your turn.

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.

Thwart

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

Saiba Cryptomancer

Flash
Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Hexproof

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

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.)

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.)

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.)

Muddle the Mixture

Counter target instant or sorcery spell.
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.)

Fabricate

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

Altar of the Brood

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

Coral Atoll

Coral Atoll enters tapped.
When Coral Atoll enters, sacrifice it unless you return an untapped Island you control to its owner's hand.
{T}: Add {C}{U}.

Walking Atlas

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

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.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Star Compass

Star Compass enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Foil

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

Mana Breach

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

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.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Island

Radiant Fountain

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

Back to Basics

Nonbasic lands don't untap during their controllers' untap steps.

Sol Ring

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.

Soratami Mirror-Mage

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

Flooded Shoreline

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

Engulf the Shore

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

Castle Vantress

Castle Vantress enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

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.

Soratami Cloudskater

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

Pongify

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