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 the battlefield tapped unless you control three or more other Islands.
When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Katsumasa, the Animator

Flying
{2}{U}: Until end of turn, target noncreature artifact you control becomes an artifact creature and gains flying. If it's not a Vehicle, it has base power and toughness 1/1 until end of turn.
At the beginning of your upkeep, put a +1/+1 counter on each of up to three target noncreature artifacts.

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.

Engulf the Shore

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

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.

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Counterspell

Trade Routes

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

Research Thief

Flash
Flying
Whenever an artifact creature you control deals combat damage to a player, draw a card.

Roil Elemental

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

Halimar Depths

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

Horn of Greed

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

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.)

Flooded Shoreline

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

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.

Marit Lage's Slumber

Whenever Marit Lage's Slumber or another snow permanent enters the battlefield under your control, scry 1.
At the beginning of your upkeep, if you control ten or more snow permanents, sacrifice Marit Lage's Slumber. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Ghost Town

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

Dreamscape Artist

{2}{U}, {T}, Discard a card, Sacrifice a land: Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Soramaro, First to Dream

Flying
Soramaro, First to Dream's power and toughness are each equal to the number of cards in your hand.
{4}, Return a land you control to its owner's hand: Draw a card.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Tiller Engine

Whenever a land enters the battlefield tapped and under your control, choose one —
• Untap that land.
• Tap target nonland permanent an opponent controls.

Saiba Cryptomancer

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

Sunder

War Room

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

Soratami Mindsweeper

Flying
{2}, Return a land you control to its owner's hand: Target player mills two cards.

Oboro Envoy

Flying
{2}, Return a land you control to its owner's hand: Target creature gets -X/-0 until end of turn, where X is the number of cards in your hand.

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.

Coral Atoll

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

Thwart

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

Guardian of Tazeem

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

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.

Sunscorched Desert

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

Moonfolk Puzzlemaker

Flying
Whenever Moonfolk Puzzlemaker becomes tapped, scry 1.

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.)

Icebreaker Kraken

This spell costs {1} less to cast for each snow land you control.
When Icebreaker Kraken enters the battlefield, artifacts and creatures target opponent controls don't untap during that player's next untap step.
Return three snow lands you control to their owner's hand: Return Icebreaker Kraken to its owner's hand.

Mana Breach

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

Guildless Commons

Guildless Commons enters the battlefield tapped.
When Guildless Commons enters the battlefield, return a land you control to its owner's hand.
{T}: Add {C}{C}.

Saprazzan Skerry

Saprazzan Skerry enters the battlefield tapped with two depletion counters on it.
{T}, Remove a depletion counter from Saprazzan Skerry: Add {U}{U}. If there are no depletion counters on Saprazzan Skerry, sacrifice it.

Finale of Revelation

Draw X cards. If X is 10 or more, instead shuffle your graveyard into your library, draw X cards, untap up to five lands, and you have no maximum hand size for the rest of the game.
Exile Finale of Revelation.

Guardians of Oboro

Defender
Modified creatures you control can attack as though they didn't have defender. (Equipment, Auras you control, and counters are modifications.)

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.

Saiba Trespassers

Channel — {3}{U}, Discard Saiba Trespassers: Tap up to two target creatures you don't control. Those creatures don't untap during their controller's next untap step.

Flow of Knowledge

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

Gush

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

Replication Specialist

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

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 enters the battlefield under your control, 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

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw 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.

Arcane Signet

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

Oboro Breezecaller

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

Terrain Generator

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

Barrin, Tolarian Archmage

When Barrin, Tolarian Archmage enters the battlefield, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.

Snow-Covered Island

Foil

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

Retreat to Coralhelm

Landfall — Whenever a land enters the battlefield under your control, 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 of your library.)

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

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.

Flow of Ideas

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.

Oboro, Palace in the Clouds

{T}: Add {U}.
{1}: Return Oboro, Palace in the Clouds 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.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Curse of the Swine

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

Sol Ring

Amulet of Vigor

Whenever a permanent enters the battlefield tapped and under your control, untap it.

Radiant Fountain

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

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Deprive

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

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 Savant

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

Walking Atlas

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

Evacuation

Return all creatures to their owners' hands.

Trench Behemoth

Return a land you control to its owner's hand: Untap Trench Behemoth. It gains hexproof until end of turn.
Landfall — Whenever a land enters the battlefield under your control, target creature an opponent controls attacks during its controller's next combat phase if able.

Thought Vessel

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

Soratami Cloudskater

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