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.)

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.

You draw a card at the beginning of the next turn's upkeep.

Target creature becomes blue until end of turn. Untap that creature.

Draw a card.

As Chameleon Spirit enters the battlefield, choose a color.

Chameleon Spirit's power and toughness are each equal to the number of permanents of the chosen color your opponents control.

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.

When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

You may exile two blue cards from your hand rather than pay this spell's mana cost.

Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters the battlefield under your control.)

Counter target spell that targets a creature.

Draw a card.

Counter target spell.

Change the text of target spell or permanent by replacing all instances of one color word with another or one basic land type with another until end of turn.

Draw a card.

Return target nonland permanent you don't control to its owner's hand.

Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

{U}, {T}: Each player reveals the top card of their library. You may put the revealed cards into their owners' graveyards. If you don't, each player draws a card.

As Declaration of Naught enters the battlefield, choose a card name.

{U}: Counter target spell with the chosen name.

As an additional cost to cast this spell, return a land you control to its owner's hand.

Counter target spell.

{1}, Exile an instant or sorcery card from your graveyard: Choose one --

• Counter target noncreature spell unless its controller pays {2}.

• Disciple of the Ring gets +1/+1 until end of turn.

• Tap target creature.

• Untap target creature.

Counter target spell with mana value 4 or greater.

Counter target instant or sorcery spell unless its controller pays {1}.

Draw a card.

You may exile a blue card with mana value X from your hand rather than pay this spell's mana cost.

Counter target spell if its mana value is X.

{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.)

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

{1}{U}: Counter target red spell.

Flash

Flying

When Draining Whelk enters the battlefield, counter target spell. Put X +1/+1 counters on Draining Whelk, where X is that spell's mana value.

When Elite Arcanist enters the battlefield, you may exile an instant card from your hand.

{X}, {T}: Copy the exiled card. You may cast the copy without paying its mana cost. X is the mana value of the exiled card.

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Look at the top X cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Flashback--{1}{U}, Exile X blue cards from your graveyard. (You may cast this card from your graveyard for its flashback cost, then exile it. You can't exile Flash of Insight to pay for its own flashback cost.)

You may discard an Island card and another card rather than pay this spell's mana cost.

Counter target spell.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

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.)

Guile can't be blocked except by three or more creatures.

If a spell or ability you control would counter a spell, instead exile that spell and you may play that card without paying its mana cost.

When Guile is put into a graveyard from anywhere, shuffle it into its owner's library.

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

Enchant creature, land, or planeswalker

Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Flying

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

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

Counter target activated ability from an artifact, creature, enchantment, or land. That permanent's activated abilities can't be activated this turn. (Mana abilities can't be targeted.)

Draw a card.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

Imprint -- When Isochron Scepter enters the battlefield, 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.

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.

At the beginning of your upkeep, you may put a verse counter on Lilting Refrain.

Sacrifice Lilting Refrain: Counter target spell unless its controller pays {X}, where X is the number of verse counters on Lilting Refrain.

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.

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Counter target spell unless its controller pays {X}.

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token.

Tap seven untapped Merfolk you control: Counter target spell.

Change the text of target spell or permanent by replacing all instances of one basic land type with another. (For example, you may change "swampwalk" to "plainswalk." This effect lasts indefinitely.)

Counter target spell unless its controller pays {3}.

{2}, Reveal X blue cards from your hand, Sacrifice Martyr of Frost: Counter target spell unless its controller pays {X}.

Search your library for a blue instant card, reveal that card, put it into your hand, then shuffle.

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.)

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.)

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.)

Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

{3}{U}, {T}: Exile another target creature you control, then return that card to the battlefield under your control.

Scry 1.

Draw a card.

Tap an untapped Wizard you control: Counter target spell unless its controller pays {1}.

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.

Draw a card at the beginning of the next turn's upkeep.

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Counter target spell. If that spell is countered this way, put it into its owner's hand instead of into that player's graveyard.

Draw a card.

Discard any number of cards. Counter target spell unless its controller pays {3} for each card discarded this way.

Blue spells you cast cost {1} less to cast.

Reveal any number of blue cards in your hand. Counter target spell unless its controller pays {1} for each card revealed this way.

{T}: Add one mana of any color.

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

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

As Shifting Sky enters the battlefield, choose a color.

All nonland permanents are the chosen color.

Flash (You may cast this spell any time you could cast an instant.)

Flying

Exploit (When this creature enters the battlefield, you may sacrifice a creature.)

When Silumgar Sorcerer exploits a creature, counter target creature spell.

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.)

Flying

{3}, Return a land you control to its owner's hand: Counter target spell unless its controller pays {3}.

Choose one --

• Change the text of target spell or permanent by replacing all instances of one basic land type with another. (This effect lasts indefinitely.)

• Change the text of target spell or permanent by replacing all instances of one color word with another. (This effect lasts indefinitely.)

Entwine {2} (Choose both if you pay the entwine cost.)

Counter target noncreature spell unless its controller pays {2}.

Counter target spell unless its controller pays {1} for each blue permanent you control.

Counter target activated ability. (Mana abilities can't be targeted.)

Draw a card.

Choose one --

• Counter target artifact spell.

• Return target artifact to its owner's hand.

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

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.

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Counter target spell or ability an opponent controls that targets a land you control. If a permanent's ability is countered this way, destroy that permanent.

Draw two cards.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Whenever Thada Adel, Acquisitor deals combat damage to a player, search that player's library for an artifact card and exile it. Then that player shuffles. Until end of turn, you may play that card.

Counter target spell unless its controller pays {X}, where X is your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

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

You may return three Islands you control to their owner's hand rather than pay this spell's mana cost.

Counter target spell.

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.

Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)

Counter target activated or triggered ability. If a permanent's ability is countered this way, activated abilities of that permanent can't be activated this turn. (Mana abilities can't be targeted.)

Counter target spell that targets a permanent you control.

{U}, {T}: Counter target spell unless its controller pays {1}.

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.

Flash (You may cast this spell any time you could cast an instant.)

When Voidmage Husher enters the battlefield, counter target activated ability. (Mana abilities can't be targeted.)

Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

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.")

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.

When Wrath of Marit Lage enters the battlefield, tap all red creatures.

Red creatures don't untap during their controllers' untap steps.