Calciform Pools

{T}: Add {C}.
{1}, {T}: Put a storage counter on Calciform Pools.
{1}, Remove X storage counters from Calciform Pools: Add X mana in any combination of {W} and/or {U}.

Altar of the Brood

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

Reflector Mage

When Reflector Mage enters the battlefield, return target creature an opponent controls to its owner's hand. That creature's owner can't cast spells with the same name as that creature until your next turn.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Omen of the Sea

Flash
When Omen of the Sea enters the battlefield, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: Scry 2.

Yorion, Sky Nomad

Companion — Your starting deck contains at least twenty cards more than the minimum deck size. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Flying
When Yorion enters the battlefield, exile any number of other nonland permanents you own and control. Return those cards to the battlefield at the beginning of the next end step.

Propaganda

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

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.

Augury Owl

Flying
When Augury Owl enters the battlefield, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Sunscape Familiar

Defender (This creature can't attack.)
Green spells and blue spells you cast cost {1} less to cast.

Wall of Omens

Defender
When Wall of Omens enters the battlefield, draw a card.

Rishadan Footpad

When Rishadan Footpad enters the battlefield, each opponent sacrifices a permanent unless they pay {2}.

Charming Prince

When Charming Prince enters the battlefield, choose one —
• Scry 2.
• You gain 3 life.
• Exile another target creature you own. Return it to the battlefield under your control at the beginning of the next end step.

Cloudchaser Kestrel

Flying
When Cloudchaser Kestrel enters the battlefield, destroy target enchantment.
{W}: Target permanent becomes white until end of turn.

Wingmate Roc

Flying
Raid — When Wingmate Roc enters the battlefield, if you attacked this turn, create a 3/4 white Bird creature token with flying.
Whenever Wingmate Roc attacks, you gain 1 life for each attacking creature.

Elite Guardmage

Flying
When Elite Guardmage enters the battlefield, you gain 3 life and draw a card.

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Teshar, Ancestor's Apostle

Flying
Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Mind Stone

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

Thunderclap Wyvern

Flash (You may cast this spell any time you could cast an instant.)
Flying
Other creatures you control with flying get +1/+1.

Arcanist's Owl

Flying
When Arcanist's Owl enters the battlefield, look at the top four cards of your library. You may reveal an artifact or enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Stormscape Familiar

Flying
White spells and black spells you cast cost {1} less to cast.

Judge's Familiar

Flying
Sacrifice Judge's Familiar: Counter target instant or sorcery spell unless its controller pays {1}.

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Azorius Signet

Sawtooth Loon

Flying
When Sawtooth Loon enters the battlefield, return a white or blue creature you control to its owner's hand.
When Sawtooth Loon enters the battlefield, draw two cards, then put two cards from your hand on the bottom of your library.

Azorius Charm

Choose one —
• Creatures you control gain lifelink until end of turn.
• Draw a card.
• Put target attacking or blocking creature on top of its owner's library.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Sage Owl

Flying
When Sage Owl enters the battlefield, look at the top four cards of your library, then put them back in any order.

Mycosynth Wellspring

When Mycosynth Wellspring enters the battlefield or is put into a graveyard from the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Rishadan Brigand

Flying
When Rishadan Brigand enters the battlefield, each opponent sacrifices a permanent unless they pay {3}.
Rishadan Brigand can block only creatures with flying.

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.

Stonehorn Dignitary

When Stonehorn Dignitary enters the battlefield, target opponent skips their next combat phase.

Pride of the Clouds

Flying
Pride of the Clouds gets +1/+1 for each other creature with flying on the battlefield.
Forecast — {2}{W}{U}, Reveal Pride of the Clouds from your hand: Create a 1/1 white and blue Bird creature token with flying. (Activate only during your upkeep and only once each turn.)

Rishadan Cutpurse

When Rishadan Cutpurse enters the battlefield, each opponent sacrifices a permanent unless they pay {1}.

Shabraz, the Skyshark

Partner with Brallin, Skyshark Rider
Flying
Whenever you draw a card, put a +1/+1 counter on Shabraz, the Skyshark and you gain 1 life.
{W/U}: Target Human gains flying until end of turn.

Skycat Sovereign

Flying
Skycat Sovereign gets +1/+1 for each other creature you control with flying.
{2}{W}{U}: Create a 1/1 white Cat Bird creature token with flying.

Act of Authority

When Act of Authority enters the battlefield, you may exile target artifact or enchantment.
At the beginning of your upkeep, you may exile target artifact or enchantment. If you do, its controller gains control of Act of Authority.

Glowing Anemone

When Glowing Anemone enters the battlefield, you may return target land to its owner's hand.

Oblivion Ring

When Oblivion Ring enters the battlefield, exile another target nonland permanent.
When Oblivion Ring leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Peregrine Drake

Flying
When Peregrine Drake enters the battlefield, untap up to five lands.

Lashknife Barrier

When Lashknife Barrier enters the battlefield, draw a card.
If a source would deal damage to a creature you control, it deals that much damage minus 1 to that creature instead.

Cloudshift

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

Dovin's Acuity

When Dovin's Acuity enters the battlefield, you gain 2 life and draw a card.
Whenever you cast an instant spell during your main phase, you may return Dovin's Acuity to its owner's hand.

Ghostly Prison

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Mulldrifter

Flying
When Mulldrifter enters the battlefield, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

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.")

Detention Sphere

When Detention Sphere enters the battlefield, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.
When Detention Sphere leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Monastery Siege

As Monastery Siege enters the battlefield, choose Khans or Dragons.
• Khans — At the beginning of your draw step, draw an additional card, then discard a card.
• Dragons — Spells your opponents cast that target you or a permanent you control cost {2} more to cast.

Soul Warden

Whenever another creature enters the battlefield, you gain 1 life.

Skycloud Expanse

Seaside Haven

{T}: Add {C}.
{W}{U}, {T}, Sacrifice a Bird: Draw a card.

Unsettled Mariner

Changeling (This card is every creature type.)
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Ephemerate // Ephemerate

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Panharmonicon

If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Lavinia of the Tenth

Protection from red
When Lavinia of the Tenth enters the battlefield, detain each nonland permanent your opponents control with mana value 4 or less. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)