You may have Phantasmal Image enter the battlefield as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

You may have Sakashima of a Thousand Faces enter the battlefield as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities. The "legend rule" doesn't apply to permanents you control. Partner (You can have two commanders if both have partner.)

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost. Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost. Counter target spell.

If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost. Exile any number of target spells.

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

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

Tap target artifact, creature, or land. Draw a card at the beginning of the next turn's upkeep.

Target creature gets -1/-0 until end of turn. Draw a card.

({U/P} can be paid with either {U} or 2 life.) Look at target player's hand. Draw a card.

Draw three cards. Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Look at the top X cards of your library, where X is the amount of mana spent to cast this spell. Put two of them into your hand and the rest on the bottom of your library in a random order. Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flying When Mulldrifter enters the battlefield, draw two cards. Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

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}.

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

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

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Switch target creature's power and toughness until end of turn. Draw a card.

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

Choose one — • Target nonsnow permanent becomes snow until end of turn. • Target snow permanent isn't snow until end of turn. Draw a card at the beginning of the next turn's upkeep.

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

{T}: Add {U}. Cephalid Coliseum deals 1 damage to you. Threshold — {U}, {T}, Sacrifice Cephalid Coliseum: Target player draws three cards, then discards three cards. Activate only if seven or more cards are in your graveyard.

({T}: Add {U}.)

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

{T}: Add {C}. {2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

{T}: Add {U}. Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

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

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

Rivendell enters the battlefield tapped unless you control a legendary creature. {T}: Add {U}. {1}{U}, {T}: Scry 2. Activate only if you control a legendary creature.

Saprazzan Skerry enters the battlefield tapped with two depletion counters on it. {T}, Remove a depletion counter from Saprazzan Skerry: Add {U}{U}. If there are no depletion counters on Saprazzan Skerry, sacrifice it.

{T}: Add {C}. {T}: Regenerate target Insect, Rat, Spider, or Squirrel. (The next time it would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Put a flood counter on target land. That land is an Island in addition to its other types for as long as it has a flood counter on it. If you control a Merfolk, draw a card.

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

Imprint — When Chrome Mox enters the battlefield, you may exile a nonartifact, nonland card from your hand. {T}: Add one mana of any of the exiled card's colors.

Flying When Cloud of Faeries enters the battlefield, untap up to two lands. Cycling {2} ({2}, Discard this card: Draw a card.)

When Coveted Jewel enters the battlefield, draw three cards. {T}: Add three mana of any one color. Whenever one or more creatures an opponent controls attack you and aren't blocked, that player draws three cards and gains control of Coveted Jewel. Untap it.

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

Buyback {2}{U} (You may pay an additional {2}{U} as you cast this spell. If you do, put this card into your hand as it resolves.) Tap target artifact, creature, or land.

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

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

Target land becomes the basic land type of your choice until end of turn. Draw a card.

{T}: Add {C}{C}.

Choose one — • Counter target spell. • Target player draws two cards. • Gain control of target nonland permanent with mana value 1 or less.

Counter target spell.

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.")

Flash When Dress Down enters the battlefield, draw a card. Creatures lose all abilities. At the beginning of the end step, sacrifice Dress Down.

If you control a commander, you may cast this spell without paying its mana cost. Counter target noncreature spell.

Flash This spell can't be countered. Whenever you cast a spell, choose up to one — • Return target spell you don't control to its owner's hand. • Return target nonland permanent to its owner's hand.

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Flash Flying When Spellstutter Sprite enters the battlefield, counter target spell with mana value X or less, where X is the number of Faeries you control.

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

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

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

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.)

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

When Spellseeker enters the battlefield, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Choose one — • Tap target permanent. • Untap target permanent. Entwine {1} (Choose both if you pay the entwine cost.)

Untap target artifact, creature, or land. Draw a card at the beginning of the next turn's upkeep.

You may tap or untap target artifact, creature, or land.