Plains

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.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Martial Coup

Create X 1/1 white Soldier creature tokens. If X is 5 or more, destroy all other creatures.

Rosie Cotton of South Lane

When Rosie Cotton enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you create a token, put a +1/+1 counter on target creature you control other than Rosie Cotton.

Priest of the Blessed Graf

At the beginning of your end step, create X 1/1 white Spirit creature tokens with flying, where X is the number of opponents who control more lands than you.

Everflowing Chalice

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

Custodi Soulbinders

This creature enters with X +1/+1 counters on it, where X is the number of other creatures on the battlefield.
{2}{W}, Remove a +1/+1 counter from this creature: Create a 1/1 white Spirit creature token with flying.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Priest of Ancient Lore

When this creature enters, you gain 1 life and draw a card.

Windbrisk Heights

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This land enters tapped.
{T}: Add {W}.
{W}, {T}: You may play the exiled card without paying its mana cost if you attacked with three or more creatures this turn.

Arcane Signet

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

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.

Impassioned Orator

Whenever another creature you control enters, you gain 1 life.

Secluded Steppe

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

Fell the Mighty

Destroy all creatures with power greater than target creature's power.

Kor Celebrant

Whenever this creature or another creature you control enters, you gain 1 life.

Angel of Invention

Flying, vigilance, lifelink
Fabricate 2 (When this creature enters, put two +1/+1 counters on it or create two 1/1 colorless Servo artifact creature tokens.)
Other creatures you control get +1/+1.

Grand Crescendo

Create X 1/1 green and white Citizen creature tokens. Creatures you control gain indestructible until end of turn.

Sierra, Nuka's Biggest Fan

The Nuka-Cola Challenge — Whenever one or more creatures you control deal combat damage to a player, put a quest counter on Sierra and create a Food token.
Whenever you sacrifice a Food, target creature you control gets +X/+X until end of turn, where X is the number of quest counters on Sierra.

Duty Beyond Death

As an additional cost to cast this spell, sacrifice a creature.
Creatures you control gain indestructible until end of turn. Put a +1/+1 counter on each creature you control. (Damage and effects that say "destroy" don't destroy those creatures.)

Abzan Battle Priest

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has lifelink.

Skyknight Squire

Whenever another creature you control enters, put a +1/+1 counter on this creature.
As long as this creature has three or more +1/+1 counters on it, it has flying and is a Knight in addition to its other types.

Basri's Solidarity

Put a +1/+1 counter on each creature you control.

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.

Apothecary White

Vigilance
Whenever you attack, you create a Food token for each player being attacked. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{W}, {T}, Tap X untapped Foods you control: Create X 1/1 white Human creature tokens.

Elspeth, Sun's Champion

+1: Create three 1/1 white Soldier creature tokens.
−3: Destroy all creatures with power 4 or greater.
−7: You get an emblem with "Creatures you control get +2/+2 and have flying."

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Captain's Call

Create three 1/1 white Soldier creature tokens.

Inspiring Leader

Commander creatures you own have "Creature tokens you control get +2/+2."

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Memorial to Glory

This land enters tapped.
{T}: Add {W}.
{3}{W}, {T}, Sacrifice this land: Create two 1/1 white Soldier creature tokens.

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.

Entrapment Maneuver

Target player sacrifices an attacking creature of their choice. You create X 1/1 white Soldier creature tokens, where X is that creature's toughness.

Sandsteppe Outcast

When this creature enters, choose one —
• Put a +1/+1 counter on this creature.
• Create a 1/1 white Spirit creature token with flying.

Helpful Hunter

Crush Contraband

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

Orzhov Advokist

At the beginning of your upkeep, each player may put two +1/+1 counters on a creature they control. If a player does, creatures that player controls can't attack you or planeswalkers you control until your next turn.

Linden, the Steadfast Queen

Vigilance (Attacking doesn't cause this creature to tap.)
Whenever a white creature you control attacks, you gain 1 life.

Ysgard's Call

Create X 1/1 white Soldier creature tokens. (Then exile this card. You may cast the artifact later from exile.)

Horn of Valhalla

Equipped creature gets +1/+1 for each creature you control.
Equip {3}

Horn of Valhalla // Ysgard's Call

Westvale Cult Leader

Westvale Cult Leader's power and toughness are each equal to the number of creatures you control.
At the beginning of your end step, create a 1/1 white and black Human Cleric creature token.

Hanweir Militia Captain

At the beginning of your upkeep, if you control four or more creatures, transform this creature.

Hanweir Militia Captain // Westvale Cult Leader

Goldnight Commander

Whenever another creature you control enters, creatures you control get +1/+1 until end of turn.

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Stalwart Pathlighter

Vigilance
Coven — At the beginning of combat on your turn, if you control three or more creatures with different powers, creatures you control gain indestructible until end of turn.

Skyclave Apparition

When this creature enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When this creature leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

The Birth of Meletis

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
II — Create a 0/4 colorless Wall artifact creature token with defender.
III — You gain 2 life.

Dazzling Angel

Flying
Whenever another creature you control enters, you gain 1 life.

Exemplar of Light

Flying
Whenever you gain life, put a +1/+1 counter on this creature.
Whenever you put one or more +1/+1 counters on this creature, draw a card. This ability triggers only once each turn.

Kabira Plateau

Kabira Takedown

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

Kabira Takedown // Kabira Plateau

Gary Clone

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Whenever this creature attacks, each creature you control named Gary Clone gets +1/+0 until end of turn.

Marshal's Anthem

Multikicker {1}{W} (You may pay an additional {1}{W} any number of times as you cast this spell.)
Creatures you control get +1/+1.
When this enchantment enters, return up to X target creature cards from your graveyard to the battlefield, where X is the number of times this enchantment was kicked.

Overseer of Vault 76

First Contact — Whenever Overseer of Vault 76 or another creature you control with power 3 or less enters, put a quest counter on Overseer of Vault 76.
At the beginning of combat on your turn, you may remove three quest counters from among permanents you control. When you do, put a +1/+1 counter on each creature you control and they gain vigilance until end of turn.

Seasoned Cathar

Ambitious Farmhand

When this creature enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
Coven — {1}{W}{W}: Transform this creature. Activate only if you control three or more creatures with different powers.

Ambitious Farmhand // Seasoned Cathar

Reverent Hoplite

When this creature enters, create a number of 1/1 white Human Soldier creature tokens equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Intrepid Adversary

Lifelink
When this creature enters, you may pay {1}{W} any number of times. When you pay this cost one or more times, put that many valor counters on this creature.
Creatures you control get +1/+1 for each valor counter on this creature.

Daxos, Blessed by the Sun

Daxos's toughness is equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Whenever another creature you control enters or dies, you gain 1 life.

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Vault 75: Middle School

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile all creatures with power 4 or greater.
II, III — Put a +1/+1 counter on each creature you control.

Light of Hope

Choose one —
• You gain 4 life.
• Destroy target enchantment.
• Put a +1/+1 counter on target creature.

Twilight Drover

Whenever a creature token leaves the battlefield, put a +1/+1 counter on this creature.
{2}{W}, Remove a +1/+1 counter from this creature: Create two 1/1 white Spirit creature tokens with flying.

Emeria Angel

Flying
Landfall — Whenever a land you control enters, you may create a 1/1 white Bird creature token with flying.

Loyal Warhound

Vigilance
When this creature 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.

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

Castle Ardenvale

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

Sigarda's Summons

Creatures you control with +1/+1 counters on them have base power and toughness 4/4, have flying, and are Angels in addition to their other types.