Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Sejiri Glacier

Sejiri Glacier enters tapped.
{T}: Add {W}.

Sejiri Shelter

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

Sejiri Shelter // Sejiri Glacier

Guildless Commons

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

Kor Skyfisher

Flying
When Kor Skyfisher enters, return a permanent you control to its owner's hand.

Secluded Steppe

Secluded Steppe enters tapped.
{T}: Add {W}.
Cycling {W} ({W}, Discard this card: Draw a card.)

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.

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Mana Tithe

Counter target spell unless its controller pays {1}.

Eiganjo Free-Riders

Flying
At the beginning of your upkeep, return a white creature you control to its owner's hand.

Cast Off

Destroy all non-Giant creatures. (Then exile this card. You may cast the creature later from exile.)

Realm-Cloaked Giant

Realm-Cloaked Giant // Cast Off

Plains

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Symmetry Matrix

Whenever a creature you control with power equal to its toughness enters, you may pay {1}. If you do, draw a card.

Your Temple Is Under Attack

Choose one —
• Pray for Protection — Creatures you control gain indestructible until end of turn.
• Strike a Deal — You and target opponent each draw two cards.

God-Eternal Oketra

Double strike
Whenever you cast a creature spell, create a 4/4 black Zombie Warrior creature token with vigilance.
When God-Eternal Oketra dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Winds of Abandon

Exile target creature you don't control. For each creature exiled this way, its controller searches their library for a basic land card. Those players put those cards onto the battlefield tapped, then shuffle.
Overload {4}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Karoo

Karoo enters tapped.
When Karoo enters, sacrifice it unless you return an untapped Plains you control to its owner's hand.
{T}: Add {C}{W}.

Rest in Peace

When Rest in Peace enters, exile all graveyards.
If a card or token would be put into a graveyard from anywhere, exile it instead.

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

Emeria Shepherd

Flying
Landfall — Whenever a land you control enters, you may return target nonland permanent card from your graveyard to your hand. If that land is a Plains, you may return that nonland permanent card to the battlefield instead.

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.

Loyal Gryff

Flash
Flying
When Loyal Gryff enters, you may return another creature you control to its owner's hand.

Whitemane Lion

Flash
When Whitemane Lion enters, return a creature you control to its owner's hand.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Rumor Gatherer

Alliance — Whenever another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.

True Conviction

Creatures you control have double strike and lifelink.

Ondu Skyruins

Ondu Skyruins enters tapped.
{T}: Add {W}.

Ondu Inversion

Ondu Inversion // Ondu Skyruins

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Sol Ring

Stormfront Riders

Flying
When Stormfront Riders enters, return two creatures you control to their owner's hand.
Whenever Stormfront Riders or another creature is returned to your hand from the battlefield, create a 1/1 white Soldier creature token.

Return to Dust

Exile target artifact or enchantment. If you cast this spell during your main phase, you may exile up to one other target artifact or enchantment.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Chop Down

Destroy target creature with power 4 or greater. (Then exile this card. You may cast the creature later from exile.)

Giant Killer

Giant Killer // Chop Down

Idyllic Grange

({T}: Add {W}.)
Idyllic Grange enters tapped unless you control three or more other Plains.
When Idyllic Grange enters untapped, put a +1/+1 counter on target creature you control.

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.

Knight of the White Orchid

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

Reveillark

Flying
When Reveillark leaves the battlefield, return up to two target creature cards with power 2 or less from your graveyard to the battlefield.
Evoke {5}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Lotus Vale

If Lotus Vale would enter, sacrifice two untapped lands instead. If you do, put Lotus Vale onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add three mana of any one color.

Lotus Field

Hexproof
Lotus Field enters tapped.
When Lotus Field enters, sacrifice two lands.
{T}: Add three mana of any one color.

Crush Contraband

Choose one or both —
• Exile target artifact.
• Exile target enchantment.

Memnite

Hour of Revelation

This spell costs {3} less to cast if there are ten or more nonland permanents on the battlefield.
Destroy all nonland permanents.

Rescuer Chwinga

Flash
Natural Shelter — When Rescuer Chwinga enters, you may return another permanent you control to its owner's hand.

Emancipation Angel

Flying
When Emancipation Angel enters, return a permanent you control to its owner's hand.

Kabira Plateau

Kabira Plateau enters tapped.
{T}: Add {W}.

Kabira Takedown

Kabira Takedown deals damage equal to the number of creatures you control to target creature or planeswalker.

Kabira Takedown // Kabira Plateau

Cut a Deal

Each opponent draws a card, then you draw a card for each opponent who drew a card this way.

Endless Atlas

{2}, {T}: Draw a card. Activate only if you control three or more lands with the same name.

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Scorched Ruins

If Scorched Ruins would enter, sacrifice two untapped lands instead. If you do, put Scorched Ruins onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {C}{C}{C}{C}.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Akroma's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Creatures you control gain flying, vigilance, and double strike until end of turn.
• Creatures you control gain lifelink, indestructible, and protection from each color until end of turn.

Aviary Mechanic

When Aviary Mechanic enters, you may return another permanent you control to its owner's hand.

Vesperlark

Flying
When Vesperlark leaves the battlefield, return target creature card with power 1 or less from your graveyard to the battlefield.
Evoke {1}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

War Room

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

Pearl Medallion

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

Stonecloaker

Flash
Flying
When Stonecloaker enters, return a creature you control to its owner's hand.
When Stonecloaker enters, exile target card from a graveyard.

Loyal Warhound

Vigilance
When Loyal Warhound enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Serra Paragon

Flying
Once during each of your turns, you may play a land from your graveyard or cast a permanent spell with mana value 3 or less from your graveyard. If you do, it gains "When this permanent is put into a graveyard from the battlefield, exile it and you gain 2 life."

Priest of Ancient Lore

When Priest of Ancient Lore enters, you gain 1 life and draw a card.

Jeskai Barricade

Flash (You may cast this spell any time you could cast an instant.)
Defender
When Jeskai Barricade enters, you may return another target creature you control to its owner's hand.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Emeria, the Sky Ruin

Emeria, the Sky Ruin enters tapped.
At the beginning of your upkeep, if you control seven or more Plains, you may return target creature card from your graveyard to the battlefield.
{T}: Add {W}.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Loyal Unicorn

Vigilance
Lieutenant — At the beginning of combat on your turn, if you control your commander, prevent all combat damage that would be dealt to creatures you control this turn. Other creatures you control gain vigilance until end of turn.

Wall of Omens

Defender
When Wall of Omens enters, draw a card.

Mind Stone

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

Ornithopter

Cartographer's Hawk

Flying
When Cartographer's Hawk deals combat damage to a player who controls more lands than you, return it to its owner's hand. If you do, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Oreskos Explorer

When Oreskos Explorer enters, search your library for up to X Plains cards, where X is the number of players who control more lands than you. Reveal those cards, put them into your hand, then shuffle.

Phyrexian Walker

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.