Kheru Spellsnatcher

Morph {4}{U}{U} (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 Kheru Spellsnatcher is turned face up, counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may cast that card without paying its mana cost for as long as it remains exiled.

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.

Ixidor, Reality Sculptor

Face-down creatures get +1/+1.
{2}{U}: Turn target face-down creature face up.

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 Ainok Survivalist is turned face up, destroy target artifact or enchantment an opponent controls.

Echo Tracer

Morph {2}{U} (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 Echo Tracer is turned face up, return target creature to its owner's hand.

Dimir Signet

Kadena, Slinking Sorcerer

The first face-down creature spell you cast each turn costs {3} less to cast.
Whenever a face-down creature you control enters, draw a card.

Misty Rainforest

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

Primordial Mist

At the beginning of your end step, you may 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.)
Exile a face-down permanent you control face up: You may play that card this turn. (You still pay its costs. Timing rules still apply.)

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

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.

Words of Wind

{1}: The next time you would draw a card this turn, each player returns a permanent they control to its owner's hand instead.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Experiment Twelve

Trample
Whenever Experiment Twelve 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.)

Alchemist's Refuge

{T}: Add {C}.
{G}{U}, {T}: You may cast spells this turn as though they had flash.

Skinthinner

Morph {3}{B}{B} (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 Skinthinner is turned face up, destroy target nonblack creature. It can't be regenerated.

Aphetto Runecaster

Whenever a permanent is turned face up, you may draw a card.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Overgrown Tomb

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

Mischievous Quanar

{3}{U}{U}: Turn Mischievous Quanar face down.
Morph {1}{U}{U} (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 Mischievous Quanar is turned face up, copy target instant or sorcery spell. You may choose new targets for that copy.

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, Temur Sabertooth gains indestructible until end of turn.

Arcane Signet

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

Bayou

Vesuvan Shapeshifter

As Vesuvan Shapeshifter enters or is turned face up, you may choose another creature on the battlefield. If you do, until Vesuvan Shapeshifter is turned face down, it becomes a copy of that creature, except it has "At the beginning of your upkeep, you may turn this creature face down."
Morph {1}{U}

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.)

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Primal Whisperer

Primal Whisperer 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.)

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.

Twilight Mire

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

Gift of Doom

Enchant creature
Enchanted creature has deathtouch and indestructible.
Morph—Sacrifice another creature. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
As Gift of Doom is turned face up, you may attach it to a creature.

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Golgari Signet

Underground Sea

Breeding Pool

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

Soul Collector

Flying
Whenever a creature dealt damage by Soul Collector this turn dies, return that card to the battlefield under your control.
Morph {B}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Deathmist Raptor

Deathtouch
Whenever a permanent you control is turned face up, you may return Deathmist Raptor 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.)

Equilibrium

Whenever you cast a creature spell, you may pay {1}. If you do, return target creature to its owner's hand.

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Den Protector

Creatures with power less than Den Protector'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 Den Protector is turned face up, return target card from your graveyard to your hand.

Flooded Grove

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

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Vedalken Orrery

You may cast spells as though they had flash.

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.)

Command Tower

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Simic Signet

Fledgling Mawcor

Flying
{T}: Fledgling Mawcor deals 1 damage to any target.
Morph {U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Island

Forest

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

Tropical Island

Sol Ring

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Yedora, Grave Gardener

Whenever another nontoken creature you control dies, you may return it to the battlefield face down under its owner's control. It's a Forest land. (It has no other types or abilities.)

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.

Crystal Shard

{3}, {T} or {U}, {T}: Return target creature to its owner's hand unless its controller pays {1}.

Swamp

Icefeather Aven

Flying
Morph {1}{G}{U} (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 Icefeather Aven is turned face up, you may return another target creature to its owner's hand.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Thran Dynamo

Secret Plans

Face-down creatures you control get +0/+1.
Whenever a permanent you control is turned face up, draw a card.

Chromeshell Crab

Morph {4}{U} (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 Chromeshell Crab is turned face up, you may exchange control of target creature you control and target creature an opponent controls.

Winding Canyons

{T}: Add {C}.
{2}, {T}: You may cast creature spells this turn as though they had flash.

Dream Chisel

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

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Master of the Veil

Morph {2}{U} (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 Master of the Veil is turned face up, you may turn target creature with a morph ability face down.

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 Nantuko Vigilante is turned face up, destroy target artifact or enchantment.

Voidmage Apprentice

Morph {2}{U}{U} (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 Voidmage Apprentice is turned face up, counter target spell.

Kadena's Silencer

When Kadena's Silencer is turned face up, counter all abilities your opponents control.
Megamorph {1}{U} (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.)

Ezuri, Claw of Progress

Whenever a creature you control with power 2 or less enters, you get an experience counter.
At the beginning of combat on your turn, put X +1/+1 counters on another target creature you control, where X is the number of experience counters you have.

Brine Elemental

Morph {5}{U}{U} (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 Brine Elemental is turned face up, each opponent skips their next untap step.

Stratus Dancer

Flying
Megamorph {1}{U} (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 Stratus Dancer is turned face up, counter target instant or sorcery spell.

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.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Primal Surge

Exile the top card of your library. If it's a permanent card, you may put it onto the battlefield. If you do, repeat this process.

Verdant Catacombs

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

Reliquary Tower

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

Willbender

Morph {1}{U} (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 Willbender is turned face up, change the target of target spell or ability with a single target.

Sunken Ruins

{T}: Add {C}.
{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Lightning Greaves

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

Printlifter Ooze

Deathtouch
Whenever Printlifter Ooze 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}

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Obscuring Aether

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

Weaver of Lies

Morph {4}{U} (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 Weaver of Lies is turned face up, turn any number of target creatures with morph abilities other than Weaver of Lies face down.

Tomb of the Spirit Dragon

{T}: Add {C}.
{2}, {T}: You gain 1 life for each colorless creature you control.