Gainsay

Cowardice

Whenever a creature becomes the target of a spell or ability, return that creature to its owner's hand. (It won't be affected by the spell or ability.)

Sea Sprite

Well-Laid Plans

Prevent all damage that would be dealt to a creature by another creature if they share a color.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

Grand Architect

Other blue creatures you control get +1/+1.
{U}: Target artifact creature becomes blue until end of turn.
Tap an untapped blue creature you control: Add {C}{C}. Spend this mana only to cast artifact spells or activate abilities of artifacts.

Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Grindstone

{3}, {T}: Target player mills two cards. If two cards that share a color were milled this way, repeat this process.

Blind Seer

{1}{U}: Target spell or permanent becomes the color of your choice until end of turn.

Ponder

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

Mind Bend

Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another. (For example, you may change "nonblack creature" to "nongreen creature" or "forestwalk" to "islandwalk." This effect lasts indefinitely.)

Sway of Illusion

Any number of target creatures become the color of your choice until end of turn.
Draw a card.

Coast Watcher

Alter Reality

Change the text of target spell or permanent by replacing all instances of one color word with another. (This effect lasts indefinitely.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dismiss into Dream

Each creature your opponents control is an Illusion in addition to its other types and has "When this creature becomes the target of a spell or ability, sacrifice it."

Wash Out

Return all permanents of the color of your choice to their owners' hands.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Fylamarid

Flying
Fylamarid can't be blocked by blue creatures.
{U}: Target creature becomes blue until end of turn.

Mind Harness

Enchant red or green creature
Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
You control enchanted creature.

Sleight of Mind

Change the text of target spell or permanent by replacing all instances of one color word with another. (For example, you may change "target black spell" to "target blue spell." This effect lasts indefinitely.)

Junk Winder

Affinity for tokens (This spell costs {1} less to cast for each token you control.)
Whenever a token you control enters, tap target nonland permanent an opponent controls. It doesn't untap during its controller's next untap step.

Hibernation

Return all green permanents to their owners' hands.

Indigo Faerie

Flying
{U}: Target permanent becomes blue in addition to its other colors until end of turn.

Metallurgic Summonings

Whenever you cast an instant or sorcery spell, create an X/X colorless Construct artifact creature token, where X is that spell's mana value.
{3}{U}{U}, Exile Metallurgic Summonings: Return all instant and sorcery cards from your graveyard to your hand. Activate only if you control six or more artifacts.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Vodalian Mystic

{T}: Target instant or sorcery spell becomes the color of your choice.

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control Willbreaker.

Shifting Sky

As Shifting Sky enters, choose a color.
All nonland permanents are the chosen color.

Pili-Pala

Flying
{2}, {Q}: Add one mana of any color. ({Q} is the untap symbol.)

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

King Crab

{1}{U}, {T}: Put target green creature on top of its owner's library.

Thought Vessel

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

Arcane Signet

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

Isochron Scepter

Imprint — When Isochron Scepter enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Douse

Homarid Shaman

Cerulean Drake

Flying
Protection from red (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything red.)
Sacrifice Cerulean Drake: Counter target spell that targets you.

Painter's Servant

As Painter's Servant enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Inundate

Return all nonblue creatures to their owners' hands.

Distorting Lens

{T}: Target permanent becomes the color of your choice until end of turn.

Veilstone Amulet

Whenever you cast a spell, creatures you control can't be the targets of spells or abilities your opponents control this turn.

Mind Stone

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

Essence Leak

Enchant permanent
As long as enchanted permanent is red or green, it has "At the beginning of your upkeep, sacrifice this permanent unless you pay its mana cost."

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Eluge, the Shoreless Sea

Eluge's power and toughness are each equal to the number of Islands you control.
Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it.
The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Sol Ring

Llawan, Cephalid Empress

When Llawan, Cephalid Empress enters, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.

Tidal Visionary

{T}: Target creature becomes the color of your choice until end of turn.

Jaded Response

Counter target spell if it shares a color with a creature you control.

High Tide

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

Island

Trail of Evidence

Whenever you cast an instant or sorcery spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Flash Flood

Choose one —
• Destroy target red permanent.
• Return target Mountain to its owner's hand.

Insight

Whenever an opponent casts a green spell, you draw a card.

Flashfreeze

Govern the Guildless

Gain control of target monocolored creature.
Forecast — {1}{U}, Reveal Govern the Guildless from your hand: Target creature becomes the color or colors of your choice until end of turn. (Activate only during your upkeep and only once each turn.)

Glamerdye

Change the text of target spell or permanent by replacing all instances of one color word with another.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Mana Maze

Players can't cast spells that share a color with the spell most recently cast this turn.

Whim of Volrath

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another until end of turn. (For example, you may change "nonred creature" to "nongreen creature" or "plainswalk" to "swampwalk.")

Brainstorm

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

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

Weatherseed Faeries

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)