Trail of Mystery

Whenever a face-down creature you control enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Whenever a permanent you control is turned face up, if it's a creature, it gets +2/+2 until end of turn.

Ainok Survivalist

Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When this creature is turned face up, destroy target artifact or enchantment an opponent controls.

Stomping Ground

({T}: Add {R} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Deathmist Raptor

Deathtouch
Whenever a permanent you control is turned face up, you may return this card from your graveyard to the battlefield face up or face down.
Megamorph {4}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Thought Vessel

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

Pyrotechnic Performer

Disguise {R} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
Whenever this creature or another creature you control is turned face up, that creature deals damage equal to its power to each opponent.

Commander's Sphere

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

Salt Road Ambushers

Whenever another permanent you control is turned face up, if it's a creature, put two +1/+1 counters on it.
Megamorph {3}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

Nantuko Vigilante

Morph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, destroy target artifact or enchantment.

Ashcloud Phoenix

Flying
When this creature dies, return it to the battlefield face down under your control.
Morph {4}{R}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, it deals 2 damage to each player.

Printlifter Ooze

Deathtouch
Whenever this creature or another creature you control is turned face up, create a 0/0 green Ooze creature token with trample. The token enters with X +1/+1 counters on it, where X is the number of other creatures you control.
Disguise {3}{G}

Obscuring Aether

Face-down creature spells you cast cost {1} less to cast.
{1}{G}: Turn this enchantment face down. (It becomes a 2/2 creature.)

Flourishing Bloom-Kin

This creature gets +1/+1 for each Forest you control.
Disguise {4}{G}
When this creature is turned face up, search your library for up to two Forest cards and reveal them. Put one of them onto the battlefield tapped and the other into your hand, then shuffle.

Ugin, the Ineffable

Colorless spells you cast cost {2} less to cast.
+1: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand.
−3: Destroy target permanent that's one or more colors.

Zoetic Cavern

{T}: Add {C}.
Morph {2} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Primal Whisperer

This creature gets +2/+2 for each face-down creature on the battlefield.
Morph {3}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Greenbelt Radical

Disguise {5}{G}{G} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this creature is turned face up, put a +1/+1 counter on each creature you control. Creatures you control gain trample until end of turn.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard this card: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Rockfall Vale

This land enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Jeweled Lotus

{T}, Sacrifice this artifact: Add three mana of any one color. Spend this mana only to cast your commander.

Akroma, Angel of Fury

This spell can't be countered.
Flying, trample, protection from white and from blue
{R}: Akroma gets +1/+0 until end of turn.
Morph {3}{R}{R}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. This artifact deals 1 damage to you.

Root Elemental

Morph {5}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, you may put a creature card from your hand onto the battlefield.

Sol Ring

Experiment Twelve

Trample
Whenever this creature or another creature you control is turned face up, put +1/+1 counters on that creature equal to its power.
Disguise {4}{G} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Temur War Shaman

When this creature enters, manifest the top card of your library. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Whenever a permanent you control is turned face up, if it's a creature, you may have it fight target creature you don't control.

Rootbound Crag

This land enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Hooded Hydra

This creature enters with X +1/+1 counters on it.
When this creature dies, create a 1/1 green Snake creature token for each +1/+1 counter on it.
Morph {3}{G}{G}
As this creature is turned face up, put five +1/+1 counters on it.

Spire Garden

This land enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Shrine of the Forsaken Gods

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless spells. Activate only if you control seven or more lands.

Command Tower

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

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Gruul Signet

Mind Stone

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

Timbercrown Pathway

Cragcrown Pathway

Cragcrown Pathway // Timbercrown Pathway

Panoptic Projektor

{T}: The next face-down creature spell you cast this turn costs {3} less to cast.
If turning a face-down permanent face up causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Dream Chisel

Face-down creature spells you cast cost {1} less to cast.

Yarus, Roar of the Old Gods

Other creatures you control have haste.
Whenever one or more face-down creatures you control deal combat damage to a player, draw a card.
Whenever a face-down creature you control dies, return it to the battlefield face down under its owner's control if it's a permanent card, then turn it face up.

Fellwar Stone

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

Mountain

Forest

Taiga

Wooded Foothills

{T}, Pay 1 life, Sacrifice this land: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, this artifact deals 3 damage to you.
{T}: Add {C}{C}.

Branch of Vitu-Ghazi

{T}: Add {C}.
Disguise {3} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this land is turned face up, add two mana of any one color. Until end of turn, you don't lose this mana as steps and phases end.

Fire-Lit Thicket

{T}: Add {C}.
{R/G}, {T}: Add {R}{R}, {R}{G}, or {G}{G}.

Scroll of Fate

{T}: Manifest a card from your hand. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Whisperwood Elemental

At the beginning of your end step, manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Sacrifice this creature: Until end of turn, face-up nontoken creatures you control gain "When this creature dies, manifest the top card of your library."

Cinder Glade

({T}: Add {R} or {G}.)
This land enters tapped unless you control two or more basic lands.

Ugin's Mastery

Whenever you cast a colorless creature spell, manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Whenever you attack with creatures with total power 6 or greater, you may turn a face-down creature you control face up.

Den Protector

Creatures with power less than this creature's power can't block it.
Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When this creature is turned face up, return target card from your graveyard to your hand.