Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Homeward Path

{T}: Add {C}.
{T}: Each player gains control of all creatures they own.

Hushbringer

Flying, lifelink
Creatures entering or dying don't cause abilities to trigger.

Sol Ring

Selfless Spirit

Flying
Sacrifice Selfless Spirit: Creatures you control gain indestructible until end of turn.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Flagstones of Trokair

{T}: Add {W}.
When Flagstones of Trokair is put into a graveyard from the battlefield, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Valkmira, Protector's Shield

If a source an opponent controls would deal damage to you or a permanent you control, prevent 1 of that damage.
Whenever you or another permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Reidane, God of the Worthy

Flying, vigilance
Snow lands your opponents control enter tapped.
Noncreature spells your opponents cast with mana value 4 or greater cost {2} more to cast.

Reidane, God of the Worthy // Valkmira, Protector's Shield

Recruiter of the Guard

When Recruiter of the Guard enters, you may search your library for a creature card with toughness 2 or less, reveal it, put it into your hand, then shuffle.

Cataclysm

Each player chooses from among the permanents they control an artifact, a creature, an enchantment, and a land, then sacrifices the rest.

Grand Abolisher

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.

Horn of the Mark

Whenever two or more creatures you control attack a player, look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Blind Obedience

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Artifacts and creatures your opponents control enter tapped.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Aether Vial

At the beginning of your upkeep, you may put a charge counter on Aether Vial.
{T}: You may put a creature card with mana value equal to the number of charge counters on Aether Vial from your hand onto the battlefield.

Minas Tirith

Minas Tirith enters tapped unless you control a legendary creature.
{T}: Add {W}.
{1}{W}, {T}: Draw a card. Activate only if you attacked with two or more creatures this turn.

Giver of Runes

{T}: Another target creature you control gains protection from colorless or from the color of your choice until end of turn.

Boromir, Warden of the Tower

Vigilance
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
Sacrifice Boromir, Warden of the Tower: Creatures you control gain indestructible until end of turn. The Ring tempts you.

Plains

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.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

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.

Sphere of Resistance

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Containment Priest

Flash
If a nontoken creature would enter and it wasn't cast, exile it instead.

Mother of Runes

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

Strict Proctor

Flying
Whenever a permanent entering causes a triggered ability to trigger, counter that ability unless its controller pays {2}.

Dolmen Gate

Prevent all combat damage that would be dealt to attacking creatures you control.

Bennie Bracks, Zoologist

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.)
At the beginning of each end step, if you created a token this turn, draw a card.

Spirit of the Labyrinth

Each player can't draw more than one card each turn.

Masako the Humorless

Flash
Tapped creatures you control can block as though they were untapped.

Adeline, Resplendent Cathar

Vigilance
Adeline, Resplendent Cathar's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Sanctifier en-Vec

Protection from black and from red
When Sanctifier en-Vec enters, exile all cards that are black or red from all graveyards.
If a black or red permanent, spell, or card not on the battlefield would be put into a graveyard, exile it instead.

Archon of Emeria

Flying
Each player can't cast more than one spell each turn.
Nonbasic lands your opponents control enter tapped.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Ethersworn Canonist

Each player who has cast a nonartifact spell this turn can't cast additional nonartifact spells.

Court of Grace

When Court of Grace enters, you become the monarch.
At the beginning of your upkeep, create a 1/1 white Spirit creature token with flying. If you're the monarch, create a 4/4 white Angel creature token with flying instead.

Skyclave Apparition

When Skyclave Apparition enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When Skyclave Apparition 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.

Thalia, Heretic Cathar

First strike
Creatures and nonbasic lands your opponents control enter tapped.

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.

Deep Gnome Terramancer

Flash
Mold Earth — Whenever one or more lands enter under an opponent's control without being played, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle. Do this only once each turn.

Hokori, Dust Drinker

Lands don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player untaps a land they control.

Champion of the Parish

Whenever another Human enters under your control, put a +1/+1 counter on Champion of the Parish.

Tocatli Honor Guard

Creatures entering don't cause abilities to trigger.

Stony Silence

Activated abilities of artifacts can't be activated.

Kataki, War's Wage

All artifacts have "At the beginning of your upkeep, sacrifice this artifact unless you pay {1}."

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Ranger-Captain of Eos

When Ranger-Captain of Eos enters, you may search your library for a creature card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
Sacrifice Ranger-Captain of Eos: Your opponents can't cast noncreature spells this turn.

Hushwing Gryff

Flash
Flying
Creatures entering don't cause abilities to trigger.

Cathar Commando

Flash (You may cast this spell any time you could cast an instant.)
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Stoneforge Mystic

When Stoneforge Mystic enters, you may search your library for an Equipment card, reveal it, put it into your hand, then shuffle.
{1}{W}, {T}: You may put an Equipment card from your hand onto the battlefield.

Thorn of Amethyst

Noncreature spells cost {1} more to cast.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

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.

Solitude

Flash
Lifelink
When Solitude enters, exile up to one other target creature. That creature's controller gains life equal to its power.
Evoke—Exile a white card from your hand.

Loran of the Third Path

Vigilance
When Loran of the Third Path enters, destroy up to one target artifact or enchantment.
{T}: You and target opponent each draw a card.

Vryn Wingmare

Flying
Noncreature spells cost {1} more to cast.

Armageddon

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Eidolon of Rhetoric

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

War Room

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

Cavern of Souls

As Cavern of Souls enters, 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, and that spell can't be countered.

Rule of Law

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Lightning Greaves

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

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.

Archivist of Oghma

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Swords to Plowshares

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

Welcoming Vampire

Flying
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.

Clever Concealment

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.)
Any number of target nonland permanents you control phase out. (Treat them and anything attached to them as though they don't exist until your next turn.)