{1}{U}: Target spell or permanent becomes the color of your choice until end of turn.
3 /
3
{1}{U}
Cerulean Drake
Creature - 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.
1 /
1
{4}{U}
Cerulean Wyvern
Creature - Drake
Flying, protection from green
3 /
3
{1}{U}
Coast Watcher
Creature - Bird Soldier
Flying, protection from green
1 /
1
{3}{U}{U}
Cowardice
Enchantment
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.)
{6}{U}
Dismiss into Dream
Enchantment
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."
{2}
Distorting Lens
Artifact
{T}: Target permanent becomes the color of your choice until end of turn.
{1}{U}{U}
Fylamarid
Creature - Squid Beast
Flying
Fylamarid can't be blocked by blue creatures.
{U}: Target creature becomes blue until end of turn.
1 /
3
{2}{U}
Hibernation
Instant
Return all green permanents to their owners' hands.
{U}
High Tide
Instant
Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.
{3}{U}
Llawan, Cephalid Empress
Legendary Creature - Cephalid Noble
When Llawan, Cephalid Empress enters the battlefield, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.
2 /
3
{3}{U}
Master of Waves
Creature - Merfolk Wizard
Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
2 /
1
{2}{U}{U}
Narwhal
Creature - Whale
First strike, protection from red
2 /
2
{3}{U}
Oraxid
Creature - Crab Beast
Protection from red
2 /
3
{3}
Scuttlemutt
Artifact Creature - Scarecrow
{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.
2 /
2
{1}{U}
Sea Sprite
Creature - Faerie
Flying, protection from red
1 /
1
{2}{U}
Shifting Sky
Enchantment
As Shifting Sky enters the battlefield, choose a color.
All nonland permanents are the chosen color.
{1}{U}
Sway of Illusion
Instant
Any number of target creatures become the color of your choice until end of turn.
Draw a card.
{2}{U}{U}
Swirl the Mists
Enchantment
As Swirl the Mists enters the battlefield, choose a color word.
All instances of color words in the text of spells and permanents are changed to the chosen color word.
{U}
Tidal Visionary
Creature - Merfolk Wizard
{T}: Target creature becomes the color of your choice until end of turn.
1 /
1
{U}
Training Grounds
Enchantment
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.
{3}{U}
Wash Out
Sorcery
Return all permanents of the color of your choice to their owners' hands.
{2}{U}
Weatherseed Faeries
Creature - Faerie
Flying, protection from red
2 /
1
{3}{U}{U}
Willbreaker
Creature - Human Wizard
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.
2 /
3
{3}{U}{U}
Wrath of Marit Lage
Enchantment
When Wrath of Marit Lage enters the battlefield, tap all red creatures.
Red creatures don't untap during their controllers' untap steps.