Plains

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Commander's Sphere

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

Théoden, King of Rohan

Whenever Théoden, King of Rohan or another Human enters the battlefield under your control, target creature gains double strike until end of turn.

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.

Denethor, Stone Seer

When Denethor, Stone Seer enters the battlefield, scry 2.
{3}{R}, {T}, Sacrifice Denethor: Target player becomes the monarch. Denethor deals 3 damage to any target.

Banishing Light

When Banishing Light enters the battlefield, exile target nonland permanent an opponent controls until Banishing Light leaves the battlefield.

Palace Jailer

When Palace Jailer enters the battlefield, you become the monarch.
When Palace Jailer enters the battlefield, exile target creature an opponent controls until an opponent becomes the monarch.

Verge Rangers

First strike
You may look at the top card of your library any time.
As long as an opponent controls more lands than you, you may play lands from the top of your library. (You can play a land this way only if you have an available land play remaining.)

Riders of Rohan

When Riders of Rohan enters the battlefield, create two 2/2 red Human Knight creature tokens with trample and haste.
Dash {4}{R}{W} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Zealous Conscripts

Haste
When Zealous Conscripts enters the battlefield, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.

Fiend Hunter

When Fiend Hunter enters the battlefield, you may exile another target creature.
When Fiend Hunter leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Command Tower

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

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Visions of Glory

Create a 1/1 white Human creature token for each creature you control.
Flashback {8}{W}{W}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Furycalm Snarl

As Furycalm Snarl enters the battlefield, you may reveal a Mountain or Plains card from your hand. If you don't, Furycalm Snarl enters the battlefield tapped.
{T}: Add {R} or {W}.

Taunt from the Rampart

Goad all creatures your opponents control. Until your next turn, those creatures can't block. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Lossarnach Captain

First strike
Whenever Lossarnach Captain or another Human enters the battlefield under your control, tap target creature an opponent controls.
At the beginning of your upkeep, create a 1/1 white Human Soldier creature token.

Vanquisher's Banner

As Vanquisher's Banner enters the battlefield, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Frontier Warmonger

Whenever one or more creatures attack one of your opponents or a planeswalker they control, those creatures gain menace until end of turn.

Dearly Departed

Flying
As long as Dearly Departed is in your graveyard, each Human creature you control enters the battlefield with an additional +1/+1 counter on it.

Flamerush Rider

Whenever Flamerush Rider attacks, create a token that's a copy of another target attacking creature and that's tapped and attacking. Exile the token at end of combat.
Dash {2}{R}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters the battlefield tapped unless you control two or more basic lands.

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature enters the battlefield under your control, Warleader's Call deals 1 damage to each opponent.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Archivist of Gondor

When your commander deals combat damage to a player, if there is no monarch, you become the monarch.
At the beginning of the monarch's end step, that player draws a card.

Fealty to the Realm

Enchant creature
When Fealty to the Realm enters the battlefield, you become the monarch.
The monarch controls enchanted creature.
Enchanted creature attacks each combat if able and can't attack you.

Forth Eorlingas!

Create X 2/2 red Human Knight creature tokens with trample and haste.
Whenever one or more creatures you control deal combat damage to one or more players this turn, you become the monarch.

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. Talisman of Conviction deals 1 damage to you.

Boromir, Gondor's Hope

Whenever Boromir, Gondor's Hope enters the battlefield or attacks, look at the top six cards of your library. You may reveal a Human or artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Combat Celebrant

If Combat Celebrant hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Frontline Medic

Battalion — Whenever Frontline Medic and at least two other creatures attack, creatures you control gain indestructible until end of turn.
Sacrifice Frontline Medic: Counter target spell with {X} in its mana cost unless its controller pays {3}.

Prince Imrahil the Fair

Whenever you draw your second card each turn, create a 1/1 white Human Soldier creature token.

Arcane Signet

Secluded Courtyard

As Secluded Courtyard enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Supreme Verdict

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

Éomer, King of Rohan

Double strike
Éomer, King of Rohan enters the battlefield with a +1/+1 counter on it for each other Human you control.
When Éomer enters the battlefield, target player becomes the monarch. Éomer deals damage equal to its power to any target.

Mountain

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 Marshal's Anthem enters the battlefield, return up to X target creature cards from your graveyard to the battlefield, where X is the number of times Marshal's Anthem was kicked.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Call for Aid

Gain control of all creatures target opponent controls until end of turn. Untap those creatures. They gain haste until end of turn. You can't attack that player this turn. You can't sacrifice those creatures this turn.

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.

Tranquil Cove

Tranquil Cove enters the battlefield tapped.
When Tranquil Cove enters the battlefield, you gain 1 life.
{T}: Add {W} or {U}.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Gimli of the Glittering Caves

Double strike
Whenever another legendary creature enters the battlefield under your control, put a +1/+1 counter on Gimli of the Glittering Caves.
Whenever Gimli deals combat damage to a player, create a Treasure token.

Oath of Eorl

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create two 1/1 white Human Soldier creature tokens.
II — Create two 2/2 red Human Knight creature tokens with trample and haste.
III — Put an indestructible counter on up to one target Human. You become the monarch.

Herald's Horn

As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Increasing Devotion

Create five 1/1 white Human creature tokens. If this spell was cast from a graveyard, create ten of those tokens instead.
Flashback {7}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Gilraen, Dúnedain Protector

{2}, {T}: Exile another target creature you control. You may return that card to the battlefield under its owner's control. If you don't, at the beginning of the next end step, return that card to the battlefield under its owner's control with a vigilance counter and a lifelink counter on it.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Heirloom Blade

Equipped creature gets +3/+1.
Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order.
Equip {1}

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Island

Champions of Minas Tirith

When Champions of Minas Tirith enters the battlefield, you become the monarch.
At the beginning of combat on each opponent's turn, if you're the monarch, that opponent may pay {X}, where X is the number of cards in their hand. If they don't, they can't attack you this combat.

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Clifftop Retreat

Clifftop Retreat enters the battlefield tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Selfless Squire

Flash
When Selfless Squire enters the battlefield, prevent all damage that would be dealt to you this turn.
Whenever damage that would be dealt to you is prevented, put that many +1/+1 counters on Selfless Squire.

Faramir, Steward of Gondor

Whenever a legendary creature with mana value 4 or greater enters the battlefield under your control, you become the monarch.
At the beginning of your end step, if you're the monarch, create two 1/1 white Human Soldier creature tokens.

Windbrisk Heights

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Windbrisk Heights enters the battlefield 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.

Erkenbrand, Lord of Westfold

Whenever Erkenbrand, Lord of Westfold or another Human enters the battlefield under your control, creatures you control get +1/+0 until end of turn.

Throne of the High City

{T}: Add {C}.
{4}, {T}, Sacrifice Throne of the High City: You become the monarch.

Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.

Swords to Plowshares

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

Aragorn, King of Gondor

Vigilance, lifelink
When Aragorn, King of Gondor enters the battlefield, you become the monarch.
Whenever Aragorn attacks, up to one target creature can't block this turn. If you're the monarch, creatures can't block this turn.

Impact Tremors

Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.

Beregond of the Guard

Whenever Beregond of the Guard or another Human enters the battlefield under your control, creatures you control get +1/+1 and gain vigilance until end of turn.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Weathered Wayfarer

{W}, {T}: Search your library for a land card, reveal it, put it into your hand, then shuffle. Activate only if an opponent controls more lands than you.

Wind-Scarred Crag

Wind-Scarred Crag enters the battlefield tapped.
When Wind-Scarred Crag enters the battlefield, you gain 1 life.
{T}: Add {R} or {W}.

Crown of Gondor

Equipped creature gets +1/+1 for each creature you control.
When a legendary creature enters the battlefield under your control, if there is no monarch, you become the monarch.
Equip {4}. This ability costs {3} less to activate if you're the monarch.

Thought Vessel

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

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Village Bell-Ringer

Flash (You may cast this spell any time you could cast an instant.)
When Village Bell-Ringer enters the battlefield, untap all creatures you control.

Sulfur Falls

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Door of Destinies

As Door of Destinies enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Lost to Legend

Put target nonland historic permanent into its owner's library fourth from the top. (Artifacts, legendaries, and Sagas are historic.)

Sol Ring

Port Town

As Port Town enters the battlefield, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters the battlefield tapped.
{T}: Add {W} or {U}.

Bastion Protector

Commander creatures you control get +2/+2 and have indestructible.

Grey Host Reinforcements

Flying, ward {3}
When Grey Host Reinforcements enters the battlefield, exile target player's graveyard. Put a number of +1/+1 counters on Grey Host Reinforcements equal to the number of creature cards exiled this way.

Éowyn, Shieldmaiden

First strike
At the beginning of combat on your turn, if another Human entered the battlefield under your control this turn, create two 2/2 red Human Knight creature tokens with trample and haste. Then if you control six or more Humans, draw a card.

Sunset Revelry

If an opponent has more life than you, you gain 4 life.
If an opponent controls more creatures than you, create two 1/1 white Human creature tokens.
If an opponent has more cards in hand than you, draw a card.

Court of Ire

When Court of Ire enters the battlefield, you become the monarch.
At the beginning of your upkeep, Court of Ire deals 2 damage to any target. If you're the monarch, it deals 7 damage instead.