High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

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.

Riptide Laboratory

{T}: Add {C}.
{1}{U}, {T}: Return target Wizard you control to its owner's hand.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

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}

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Aphetto Alchemist

{T}: Untap target artifact or creature.
Morph {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.)

Ixidron

As Ixidron enters, turn all other nontoken creatures face down. (They're 2/2 creatures.)
Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.

Dermoplasm

Flying
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 Dermoplasm is turned face up, you may put a creature card with a morph ability from your hand onto the battlefield face up. If you do, return Dermoplasm to its owner's hand.

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.

Thousand Winds

Flying
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 Thousand Winds is turned face up, return all other tapped creatures to their owners' hands.

Fathom Seer

Morph—Return two Islands you control to their owner's hand. (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 Fathom Seer is turned face up, draw two cards.

Disruptive Pitmage

{T}: Counter target spell unless its controller pays {1}.
Morph {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.)

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.

Monastery Loremaster

Megamorph {5}{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 Monastery Loremaster is turned face up, return target noncreature, nonland card from your graveyard to your hand.

Long-Term Plans

Search your library for a card, then shuffle and put that card third from the top.

Cryptic Coat

When Cryptic Coat enters, cloak the top card of your library, then attach Cryptic Coat to it. (To cloak a card, put it onto the battlefield face down as a 2/2 creature with ward {2}. Turn it face up any time for its mana cost if it's a creature card.)
Equipped creature gets +1/+0 and can't be blocked.
{1}{U}: Return Cryptic Coat to its owner's hand.

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.

Silumgar Spell-Eater

Megamorph {4}{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 Silumgar Spell-Eater is turned face up, counter target spell unless its controller pays {3}.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Voidmage Prodigy

{U}{U}, Sacrifice a Wizard: Counter target spell.
Morph {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.)

Omarthis, Ghostfire Initiate

Omarthis, Ghostfire Initiate enters with X +1/+1 counters on it.
Whenever you put one or more +1/+1 counters on another colorless creature, you may put a +1/+1 counter on Omarthis.
When Omarthis dies, manifest a number of cards from the top of your library equal to the number of counters on it.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Raven Guild Master

Whenever Raven Guild Master deals combat damage to a player, that player exiles the top ten cards of their library.
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.)

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 Branch of Vitu-Ghazi 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.

Mistfire Weaver

Flying
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 Mistfire Weaver is turned face up, target creature you control gains hexproof until end of turn.

Cyber Conversion

Turn target creature face down. It's a 2/2 Cyberman artifact creature.

Step Through

Return two target creatures to their owners' hands.
Wizardcycling {2} ({2}, Discard this card: Search your library for a Wizard card, reveal it, put it into your hand, then shuffle.)

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.)

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

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.

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.

Ixidor, Reality Sculptor

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

Thought Vessel

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

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.

Island

Arcane Signet

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

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.

Qarsi Deceiver

{T}: Add {C}. Spend this mana only to cast a face-down creature spell, pay a mana cost to turn a manifested creature face up, or pay a morph cost. (A megamorph cost is a morph cost.)

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.)

Cloudform

When Cloudform enters, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Cloudform to it. (To manifest a card, 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.)
Enchanted creature has flying and hexproof.

Apprentice Wizard

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.

Dream Chisel

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

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

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.)

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.

Coveted Falcon

Flying
Whenever Coveted Falcon attacks, gain control of target permanent you own but don't control.
Disguise {1}{U}
When Coveted Falcon is turned face up, target opponent gains control of any number of target permanents you control. Draw a card for each one they gained control of this way.

Crystal Shard

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

Exit Specialist

Exit Specialist can't be blocked by creatures with power 3 or greater.
Disguise {1}{U} (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 Exit Specialist is turned face up, return another target creature to its owner's hand.

Plant Tadpoles

Tap X target creatures. They don't untap during their controllers' next untap steps. (Then exile this card. You may cast the creature later from exile.)

Illithid Harvester

Ceremorphosis — When Illithid Harvester enters, turn any number of target tapped nontoken creatures face down. They're 2/2 Horror creatures.

Illithid Harvester // Plant Tadpoles

Backslide

Turn target creature with a morph ability face down.
Cycling {U} ({U}, Discard this card: Draw a card.)

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Jeskai Infiltrator

Jeskai Infiltrator can't be blocked as long as you control no other creatures.
When Jeskai Infiltrator deals combat damage to a player, exile it and the top card of your library in a face-down pile, shuffle that pile, then manifest those cards. (To manifest a card, 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.)

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Sol Ring

Tomb of the Spirit Dragon

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

Homeward Path

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

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.)

Aphetto Runecaster

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

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

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.

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Liberator, Urza's Battlethopter

Flash
Flying
You may cast colorless spells and artifact spells as though they had flash.
Whenever you cast a spell, if the amount of mana spent to cast that spell is greater than Liberator, Urza's Battlethopter's power, put a +1/+1 counter on Liberator.

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.

Counterspell

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.

Reliquary Tower

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

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.

Riptide Entrancer

Whenever Riptide Entrancer deals combat damage to a player, you may sacrifice it. If you do, gain control of target creature that player controls. (This effect lasts indefinitely.)
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.)

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.