Plains

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

New Benalia

New Benalia enters tapped.
When New Benalia enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W}.

Patient Rebuilding

At the beginning of your upkeep, target opponent mills three cards, then you draw a card for each land card put into their graveyard this way.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Unwind

Counter target noncreature spell. Untap up to three lands.

Rule of Law

Each player can't cast more than one spell each turn.

Deeproot Pilgrimage

Whenever one or more nontoken Merfolk you control become tapped, create a 1/1 blue Merfolk creature token with hexproof.

Runed Halo

As Runed Halo enters, choose a card name.
You have protection from the chosen card name. (You can't be targeted, dealt damage, or enchanted by anything with that name.)

Circle of Protection: White

{1}: The next time a white source of your choice would deal damage to you this turn, prevent that damage.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Circle of Protection: Red

{1}: The next time a red source of your choice would deal damage to you this turn, prevent that damage.

Master of the Pearl Trident

Other Merfolk creatures you control get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Phantasmal Terrain

Enchant land
As Phantasmal Terrain enters, choose a basic land type.
Enchanted land is the chosen type.

Commanding Presence

Enchant creature
Enchanted creature gets +2/+2 and has first strike and "Whenever this creature deals combat damage to a player, create a 1/1 white Human Soldier creature token."

Protean Thaumaturge

Constellation — Whenever an enchantment you control enters, you may have Protean Thaumaturge become a copy of another target creature, except it has this ability.

Circle of Protection: Blue

{1}: The next time a blue source of your choice would deal damage to you this turn, prevent that damage.

Cleric of Chill Depths

Whenever Cleric of Chill Depths blocks a creature, that creature doesn't untap during its controller's next untap step.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Fog Bank

Defender (This creature can't attack.)
Flying
Prevent all combat damage that would be dealt to and dealt by this creature.

Prismatic Ward

Enchant creature
As Prismatic Ward enters, choose a color.
Prevent all damage that would be dealt to enchanted creature by sources of the chosen color.

Starfield Mystic

Enchantment spells you cast cost {1} less to cast.
Whenever an enchantment you control is put into a graveyard from the battlefield, put a +1/+1 counter on Starfield Mystic.

Sentinel of the Pearl Trident

Flash
When Sentinel of the Pearl Trident enters, you may exile target historic permanent you control. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step. (Artifacts, legendaries, and Sagas are historic.)

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Dawnhart Geist

Whenever you cast an enchantment spell, you gain 2 life.

Memorial to Genius

Memorial to Genius enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Sigil of the New Dawn

Whenever a creature is put into your graveyard from the battlefield, you may pay {1}{W}. If you do, return that card to your hand.

Disperse

Return target nonland permanent to its owner's hand.

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Story Circle

As Story Circle enters, choose a color.
{W}: The next time a source of your choice of the chosen color would deal damage to you this turn, prevent that damage.

Circle of Confinement

When Circle of Confinement enters, exile target creature an opponent controls with mana value 3 or less until Circle of Confinement leaves the battlefield.
Whenever an opponent casts a Vampire spell with the same name as a card exiled with Circle of Confinement, you gain 2 life.

Island

Tragic Poet

{T}, Sacrifice Tragic Poet: Return target enchantment card from your graveyard to your hand.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Frozen Aether

Artifacts, creatures, and lands your opponents control enter tapped.

Mist-Cloaked Herald

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

Circle of Protection: Black

{1}: The next time a black source of your choice would deal damage to you this turn, prevent that damage.

Word of Undoing

Return target creature and all white Auras you own attached to it to their owners' hands.

Eyes Everywhere

At the beginning of your upkeep, scry 1.
{5}{U}: Exchange control of Eyes Everywhere and target nonland permanent. Activate only as a sorcery.

Circle of Protection: Green

{1}: The next time a green source of your choice would deal damage to you this turn, prevent that damage.