Sea of Clouds

Sea of Clouds enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Chancellor of the Spires

You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, each opponent mills seven cards.
Flying
When Chancellor of the Spires enters the battlefield, you may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.

Broken Ambitions

Counter target spell unless its controller pays {X}. Clash with an opponent. If you win, that spell's controller mills four cards. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Keeper of the Accord

At the beginning of each opponent's end step, if that player controls more creatures than you, create a 1/1 white Soldier creature token.
At the beginning of each opponent's end step, if that player controls more lands than you, you may search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Archive Trap

If an opponent searched their library this turn, you may pay {0} rather than pay this spell's mana cost.
Target opponent mills thirteen cards.

Restless Vinestalk

Restless Vinestalk enters the battlefield tapped.
{T}: Add {G} or {U}.
{3}{G}{U}: Until end of turn, Restless Vinestalk becomes a 5/5 green and blue Plant creature with trample. It's still a land.
Whenever Restless Vinestalk attacks, up to one other target creature has base power and toughness 3/3 until end of turn.

Bond of Insight

Each player mills four cards. Return up to two instant and/or sorcery cards from your graveyard to your hand. Exile Bond of Insight.

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.)

Restless Anchorage

Restless Anchorage enters the battlefield tapped.
{T}: Add {W} or {U}.
{1}{W}{U}: Until end of turn, Restless Anchorage becomes a 2/3 white and blue Bird creature with flying. It's still a land.
Whenever Restless Anchorage attacks, create a Map token.

Lumbering Falls

Lumbering Falls enters the battlefield tapped.
{T}: Add {G} or {U}.
{2}{G}{U}: Lumbering Falls becomes a 3/3 green and blue Elemental creature with hexproof until end of turn. It's still a land.

Breeding Pool

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

Armored Skaab

When Armored Skaab enters the battlefield, mill four cards.

Cloudhoof Kirin

Flying
Whenever you cast a Spirit or Arcane spell, you may have target player mill X cards, where X is that spell's mana value.

Thran Dynamo

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Brain Freeze

Target player mills three cards.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Astral Drift

Whenever you cycle Astral Drift or cycle another card while Astral Drift is on the battlefield, you may exile target creature. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step.
Cycling {2}{W} ({2}{W}, Discard this card: Draw a card.)

Sol Ring

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Knight of the White Orchid

First strike
When Knight of the White Orchid enters the battlefield, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Scythe of the Wretched

Equipped creature gets +2/+2.
Whenever a creature dealt damage by equipped creature this turn dies, return that card to the battlefield under your control. Attach Scythe of the Wretched to that creature.
Equip {4}

Teleportation Circle

At the beginning of your end step, exile up to one target artifact or creature you control, then return that card to the battlefield under its owner's control.

Misty Rainforest

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

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.)

Compelling Argument

Target player mills five cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Quandrix Cultivator

When Quandrix Cultivator enters the battlefield, you may search your library for a basic Forest or Island card, put it onto the battlefield, then shuffle.

Lush Portico

({T}: Add {G} or {W}.)
Lush Portico enters the battlefield tapped.
When Lush Portico enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Commander's Plate

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander {3}
Equip {5}

Forest

Aftermath Analyst

When Aftermath Analyst enters the battlefield, mill three cards.
{3}{G}, Sacrifice Aftermath Analyst: Return all land cards from your graveyard to the battlefield tapped.

Boreas Charger

Flying
When Boreas Charger leaves the battlefield, choose an opponent who controls more lands than you. Search your library for a number of Plains cards equal to the difference, reveal those cards, put one of them onto the battlefield tapped and the rest into your hand, then shuffle.

Cabaretti Courtyard

When Cabaretti Courtyard enters the battlefield, sacrifice it. When you do, search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Siren's Ruse

Exile target creature you control, then return that card to the battlefield under its owner's control. If a Pirate was exiled this way, draw a card.

Cut Your Losses

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Target player mills half their library, rounded down.

Simic Signet

Coiling Oracle

When Coiling Oracle enters the battlefield, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Soulherder

Whenever a creature is exiled from the battlefield, put a +1/+1 counter on Soulherder.
At the beginning of your end step, you may exile another target creature you control, then return that card to the battlefield under its owner's control.

Teferi's Isle

Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.)
Teferi's Isle enters the battlefield tapped.
{T}: Add {U}{U}.

Brokers Hideout

When Brokers Hideout enters the battlefield, sacrifice it. When you do, search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Chromatic Lantern

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

Chulane, Teller of Tales

Vigilance
Whenever you cast a creature spell, draw a card, then you may put a land card from your hand onto the battlefield.
{3}, {T}: Return target creature you control to its owner's hand.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Derevi, Empyrial Tactician

Flying
Whenever Derevi, Empyrial Tactician enters the battlefield or a creature you control deals combat damage to a player, you may tap or untap target permanent.
{1}{G}{W}{U}: Put Derevi onto the battlefield from the command zone.

Turn to Mist

Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Restless Prairie

Restless Prairie enters the battlefield tapped.
{T}: Add {G} or {W}.
{2}{G}{W}: Restless Prairie becomes a 3/3 green and white Llama creature until end of turn. It's still a land.
Whenever Restless Prairie attacks, other creatures you control get +1/+1 until end of turn.

Razortide Bridge

Razortide Bridge enters the battlefield tapped.
Indestructible
{T}: Add {W} or {U}.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Otherworldly Journey

Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner's control with a +1/+1 counter on it.

Arctic Treeline

({T}: Add {G} or {W}.)
Arctic Treeline enters the battlefield tapped.

Command Tower

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

Meandering River

Meandering River enters the battlefield tapped.
{T}: Add {W} or {U}.

Radiant Grove

({T}: Add {G} or {W}.)
Radiant Grove enters the battlefield tapped.

Mind Stone

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

Chill of Foreboding

Each player mills five cards.
Flashback {7}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Azorius Signet

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Liberate

Exile target creature you control. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Plains

Didn't Say Please

Counter target spell. Its controller mills three cards.

The Eternal Wanderer

No more than one creature can attack The Eternal Wanderer each combat.
+1: Exile up to one target artifact or creature. Return that card to the battlefield under its owner's control at the beginning of that player's next end step.
0: Create a 2/2 white Samurai creature token with double strike.
−4: For each player, choose a creature that player controls. Each player sacrifices all creatures they control not chosen this way.

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.

Arrester's Admonition

Return target creature to its owner's hand.
Addendum — If you cast this spell during your main phase, draw a card.

Mistmeadow Vanisher

Whenever Mistmeadow Vanisher becomes tapped, exile up to one target nonland, nontoken permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Selesnya Signet

Restoration Angel

Flash
Flying
When Restoration Angel enters the battlefield, you may exile target non-Angel creature you control, then return that card to the battlefield under your control.

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Justiciar's Portal

Exile target creature you control, then return that card to the battlefield under its owner's control. It gains first strike until end of turn.

Overflowing Basin

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Reliquary Tower

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

Argoth, Sanctum of Nature

Argoth, Sanctum of Nature enters the battlefield tapped unless you control a legendary green creature.
{T}: Add {G}.
{2}{G}{G}, {T}: Create a 2/2 green Bear creature token, then mill three cards. Activate only as a sorcery.
(Melds with Titania, Voice of Gaea.)

Quandrix Campus

Quandrix Campus enters the battlefield tapped.
{T}: Add {G} or {U}.
{4}, {T}: Scry 1.

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Fetch Quest

Mill seven cards. Then put a creature, enchantment, or land card from among the milled cards onto the battlefield.

Bramble Familiar

{T}: Add {G}.
{1}{G}, {T}, Discard a card: Return Bramble Familiar to its owner's hand.

Bramble Familiar // Fetch Quest

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Felidar Guardian

When Felidar Guardian enters the battlefield, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.

Kodama's Reach

Cathartic Adept

Altar of the Brood

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Adarkar Valkyrie

Flying, vigilance
{T}: When target creature other than Adarkar Valkyrie dies this turn, return that card to the battlefield under your control.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Blossoming Tortoise

Whenever Blossoming Tortoise enters the battlefield or attacks, mill three cards, then return a land card from your graveyard to the battlefield tapped.
Activated abilities of lands you control cost {1} less to activate.
Land creatures you control get +1/+1.