Thought Vessel

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

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Shark Typhoon

Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's mana value.
Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.)
When you cycle this card, create an X/X blue Shark creature token with flying.

Worn Powerstone

This artifact enters tapped.
{T}: Add {C}{C}.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Tribute Mage

When this creature enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Gilded Lotus

Nexus of Fate

Take an extra turn after this one.
If Nexus of Fate would be put into a graveyard from anywhere, reveal Nexus of Fate and shuffle it into its owner's library instead.

Thryx, the Sudden Storm

Flash (You may cast this spell any time you could cast an instant.)
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Lórien Revealed

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.)

Brinelin, the Moon Kraken

When Brinelin enters and whenever you cast a spell with mana value 6 or greater, you may return target nonland permanent to its owner's hand.
Partner (You can have two commanders if both have partner.)

Scourge of Fleets

When this creature enters, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

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.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Mystic Confluence

Choose three. You may choose the same mode more than once.
• Counter target spell unless its controller pays {3}.
• Return target creature to its owner's hand.
• Draw a card.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Access Denied

Counter target spell. Create X 1/1 colorless Thopter artifact creature tokens with flying, where X is that spell's mana value.

This Town Ain't Big Enough

This spell costs {3} less to cast if it targets a permanent you control.
Return up to two target nonland permanents to their owners' hands.

Treasure Cruise

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

Flow of Ideas

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Sky Diamond

This artifact enters tapped.
{T}: Add {U}.

Spectral Deluge

Return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.
Foretell {1}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Perplexing Test

Choose one —
• Return all creature tokens to their owners' hands.
• Return all nontoken creatures to their owners' hands.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

High Tide

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

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Torrential Gearhulk

Flash
When this creature enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Mystical Tutor

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

Time Stop

End the turn. (Exile all spells and abilities, including this spell. The player whose turn it is discards down to their maximum hand size. Damage heals and "this turn" and "until end of turn" effects end.)

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Memory

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Each player shuffles their hand and graveyard into their library, then draws seven cards.

Commit

Put target spell or nonland permanent into its owner's library second from the top.

Commit // Memory

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Mulldrifter

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

Merchant Scroll

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

Trinket Mage

When this creature enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Swan Song

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

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Arcane Signet

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

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Coil and Catch

Draw three cards, then discard a card. (Then shuffle this card into its owner's library.)

Marang River Regent

Flying
When this creature enters, return up to two other target nonland permanents to their owners' hands.

Marang River Regent // Coil and Catch

Defiler of Dreams

Flying
As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay.
Whenever you cast a blue permanent spell, draw a card.

Mystic Remora

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}.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Aetherspouts

For each attacking creature, its owner puts it on their choice of the top or bottom of their library.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Sapphire Medallion

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

Into the Story

This spell costs {3} less to cast if an opponent has seven or more cards in their graveyard.
Draw four cards.

Archmage of Runes

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, draw a card.

Excalibur, Sword of Eden

This spell costs {X} less to cast, where X is the total mana value of historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)
Equipped creature gets +10/+0 and has vigilance.
Equip legendary creature {2}

Evacuation

Return all creatures to their owners' hands.

Raise the Palisade

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

Trophy Mage

When this creature enters, you may search your library for an artifact card with mana value 3, reveal it, put it into your hand, then shuffle.

Caged Sun

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

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.

Sol Ring

Island

Time Warp

Target player takes an extra turn after this one.

Ponder

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

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on this artifact.
At the beginning of each upkeep, put an hour counter on this artifact.
When the twelfth hour counter is put on this artifact, shuffle your hand and graveyard into your library, then draw seven cards. Exile this artifact.

Treasure Mage

When this creature enters, you may search your library for an artifact card with mana value 6 or greater, reveal it, put it into your hand, then shuffle.

Thran Dynamo

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

Reliquary Tower

Precognitive Perception

Draw three cards.
Addendum — If you cast this spell during your main phase, instead scry 3, then draw three cards.