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.

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser enters, return target spell or permanent to its owner's hand.

Spark Double

You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Moonlace

Target spell or permanent becomes colorless.

Trait Doctoring

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.)

Leap

Target creature gains flying until end of turn.
Draw a card.

Shadow Rift

Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Draw a card.

Thermal Flux

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.

Twisted Image

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

Orvar, the All-Form

Changeling
Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.
When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

Voracious Bibliophile

Flying, vigilance
Whenever you cast a spell with one or more targets, draw that many cards.

Clockspinning

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Choose a counter on target permanent or suspended card. Remove that counter from that permanent or card or put another of those counters on it.

Shipwreck Dowser

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Shimmering Mirage

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

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.")

Mind Games

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.

Fleeting Distraction

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

Twiddle

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

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Sapphire Medallion

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

Archmage Emeritus

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

Isochron Scepter

Imprint — When this artifact 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.

Cloudpost

This land enters tapped.
{T}: Add {C} for each Locus on the battlefield.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Cerulean Wisps

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

Glimmerpost

When this land enters, you gain 1 life for each Locus on the battlefield.
{T}: Add {C}.

Sakashima of a Thousand Faces

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

Arcane Denial

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.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Snow-Covered Island

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.)

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have this creature enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Vesuvan Duplimancy

Whenever you cast a spell that targets only a single artifact or creature you control, create a token that's a copy of that artifact or creature, except it's not legendary.

Spellseeker

When this creature enters, 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.

Mizzium Skin

Target creature you control gets +0/+1 and gains hexproof until end of turn.
Overload {1}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Sol Ring

Enervate

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

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Riptide Laboratory

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

Dream's Grip

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

Jinx

Target land becomes the basic land type of your choice until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Aquitect's Will

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.

Slip Through Space

Devoid (This card has no color.)
Target creature can't be blocked this turn.
Draw a card.

Mystic Sanctuary

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

Arcane Signet

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

Hullbreaker Horror

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.

Hidden Strings

You may tap or untap target permanent, then you may tap or untap another target permanent.
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.)

Chilling Trap

Target creature gets -4/-0 until end of turn. If you control a Wizard, draw a card.

Ghostly Flicker

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

Essence Flux

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.

Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Energy Tap

Tap target untapped creature you control. If you do, add an amount of {C} equal to that creature's mana value.