Jaya Ballard, Task Mage

{R}, {T}, Discard a card: Destroy target blue permanent.
{1}{R}, {T}, Discard a card: Jaya Ballard, Task Mage deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.
{5}{R}{R}, {T}, Discard a card: Jaya Ballard deals 6 damage to each creature and each player.

Pyroblast

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

Active Volcano

Choose one —
• Destroy target blue permanent.
• Return target Island to its owner's hand.

Celestial Dawn

Lands you control are Plains.
Nonland permanents you control are white. The same is true for spells you control and nonland cards you own that aren't on the battlefield.
You may spend white mana as though it were mana of any color. You may spend other mana only as though it were colorless mana.

Paragon of Eternal Wilds

Other green creatures you control get +1/+1.
{G}, {T}: Another target green creature you control gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Hunter's Mark

This spell costs {3} less to cast if it targets a blue permanent you don't control.
This spell can't be countered.
Target creature you control gets +1/+1 until end of turn. Then it deals damage equal to its power to target creature or planeswalker you don't control.

Thoughtlace

Target spell or permanent becomes blue. (Mana symbols on that permanent remain unchanged.)

Paragon of Fierce Defiance

Other red creatures you control get +1/+1.
{R}, {T}: Another target red creature you control gains haste until end of turn. (It can attack and {T} this turn.)

Wrenn and Realmbreaker

Lands you control have "{T}: Add one mana of any color."
+1: Up to one target land you control becomes a 3/3 Elemental creature with vigilance, hexproof, and haste until your next turn. It's still a land.
−2: Mill three cards. You may put a permanent card from among the milled cards into your hand.
−7: You get an emblem with "You may play lands and cast permanent spells from your graveyard."

Disciple of Kangee

{U}, {T}: Target creature gains flying and becomes blue until end of turn.

This spell can't be countered.
Fry deals 5 damage to target creature or planeswalker that's white or blue.

Tidal Visionary

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

Command Tower

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

Day's Undoing

Each player shuffles their hand and graveyard into their library, then draws seven cards. If it's your turn, end the turn. (Exile all spells and abilities from the stack, including this card. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Parch

Choose one —
• Parch deals 2 damage to any target.
• Parch deals 4 damage to target blue creature.

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.)

Raka Sanctuary

At the beginning of your upkeep, if you control a white or blue permanent, Raka Sanctuary deals 1 damage to target creature. If you control a white permanent and a blue permanent, Raka Sanctuary deals 3 damage instead.

Lifelace

Target spell or permanent becomes green. (Mana symbols on that permanent remain unchanged.)

Lightning Dart

Lightning Dart deals 1 damage to target creature. If that creature is white or blue, Lightning Dart deals 4 damage to it instead.

Blind Seer

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

Balduvian Shaman

{T}: Change the text of target white enchantment you control that doesn't have cumulative upkeep by replacing all instances of one color word with another. (For example, you may change "black creatures can't attack" to "blue creatures can't attack.") That enchantment gains "Cumulative upkeep {1}." (At the beginning of its controller's upkeep, that player puts an age counter on it, then sacrifices it unless they pay its upkeep cost for each age counter on it.)

Forest

Island

Clear the Mind

Target player shuffles their graveyard into their library.
Draw a card.

Douse

Crimson Wisps

Target creature becomes red and gains haste until end of turn. (It can attack and {T} this turn.)
Draw a card.

Quickchange

Target creature becomes the color or colors of your choice until end of turn.
Draw a card.

Reality

Illusion

Target spell or permanent becomes the color of your choice until end of turn.

Illusion // Reality

Scuttlemutt

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

Dwarven Song

One or more target creatures become red until end of turn.

Heaven's Gate

One or more target creatures become white until end of turn.

Singe

Singe deals 1 damage to target creature. That creature becomes black until end of turn.

Purelace

Target spell or permanent becomes white. (Mana symbols on that permanent remain unchanged.)

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.

Metathran Transport

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

Plains

Rending Volley

This spell can't be countered.
Rending Volley deals 4 damage to target white or blue creature.

Northern Paladin

{W}{W}, {T}: Destroy target black permanent.

Aragorn, the Uniter

Whenever you cast a white spell, create a 1/1 white Human Soldier creature token.
Whenever you cast a blue spell, scry 2.
Whenever you cast a red spell, Aragorn, the Uniter deals 3 damage to target opponent.
Whenever you cast a green spell, target creature gets +4/+4 until end of turn.

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.

Sea Kings' Blessing

One or more target creatures become blue until end of turn.

Viridescent Wisps

Target creature becomes green and gets +1/+0 until end of turn.
Draw a card.

Cerulean Wisps

Target creature becomes blue until end of turn. Untap that creature.
Draw a card.

Display of Dominance

Choose one —
• Destroy target blue or black noncreature permanent.
• Permanents you control can't be the targets of blue or black spells your opponents control this turn.

Clout of the Dominus

Enchant creature
As long as enchanted creature is blue, it gets +1/+1 and has shroud. (It can't be the target of spells or abilities.)
As long as enchanted creature is red, it gets +1/+1 and has haste.

Mountain

Cloudchaser Kestrel

Flying
When Cloudchaser Kestrel enters, destroy target enchantment.
{W}: Target permanent becomes white until end of turn.

Blue Elemental Blast

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

Lifeforce

Gainsay

Ana Sanctuary

At the beginning of your upkeep, if you control a blue or black permanent, target creature gets +1/+1 until end of turn. If you control a blue permanent and a black permanent, that creature gets +5/+5 until end of turn instead.

Jace's Defeat

Counter target blue spell. If it was a Jace planeswalker spell, scry 2.

Niveous Wisps

Target creature becomes white until end of turn. Tap that creature.
Draw a card.

Combust

This spell can't be countered.
Combust deals 5 damage to target white or blue creature. The damage can't be prevented.

Sylvan Paradise

One or more target creatures become green until end of turn.

Alchor's Tomb

{2}, {T}: Target permanent you control becomes the color of your choice. (This effect lasts indefinitely.)

Flash Flood

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

Southern Paladin

{W}{W}, {T}: Destroy target red permanent.

Red Elemental Blast

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

Aurora Griffin

Flying
{W}: Target permanent becomes white until end of turn.

Paragon of New Dawns

Other white creatures you control get +1/+1.
{W}, {T}: Another target white creature you control gains vigilance until end of turn. (Attacking doesn't cause it to tap.)

Lithomantic Barrage

This spell can't be countered.
Lithomantic Barrage deals 1 damage to target creature or planeswalker. It deals 5 damage instead if that target is white and/or blue.

Quicksilver Elemental

{U}: Quicksilver Elemental gains all activated abilities of target creature until end of turn. (If any of the abilities use that creature's name, use this creature's name instead.)
You may spend blue mana as though it were mana of any color to pay the activation costs of Quicksilver Elemental's abilities.

Sway of Illusion

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

Eight-and-a-Half-Tails

{1}{W}: Target permanent you control gains protection from white until end of turn.
{1}: Target spell or permanent becomes white until end of turn.

Indigo Faerie

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

Sisay's Ingenuity

Enchant creature
When Sisay's Ingenuity enters, draw a card.
Enchanted creature has "{2}{U}: Target creature becomes the color of your choice until end of turn."

Paragon of Gathering Mists

Other blue creatures you control get +1/+1.
{U}, {T}: Another target blue creature you control gains flying until end of turn.

Fylamarid

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

Autumn's Veil

Spells you control can't be countered by blue or black spells this turn, and creatures you control can't be the targets of blue or black spells this turn.

Distorting Lens

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

Chaoslace

Target spell or permanent becomes red. (Its mana symbols remain unchanged.)

Ersatz Gnomes

{T}: Target spell becomes colorless.
{T}: Target permanent becomes colorless until end of turn.

Order of the Sacred Torch

{T}, Pay 1 life: Counter target black spell.

Prismatic Lace

Target permanent becomes the color or colors of your choice. (This effect lasts indefinitely.)

Swirling Spriggan

{G/U}{G/U}: Target creature you control becomes the color or colors of your choice until end of turn.