Swarm Intelligence

Whenever you cast an instant or sorcery spell, you may copy that spell. You may choose new targets for the copy.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter 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.)

Unsummon

Return target creature to its owner's hand.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Petty Theft

Return target nonland permanent an opponent controls to its owner's hand.

Brazen Borrower

Flash
Flying
Brazen Borrower can block only creatures with flying.

Brazen Borrower // Petty Theft

Spell Satchel

Magecraft — Whenever you cast or copy an instant or sorcery spell, put a book counter on Spell Satchel.
{T}, Remove a book counter from Spell Satchel: Add {C}.
{3}, {T}, Remove three book counters from Spell Satchel: Draw a card.

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Epiphany at the Drownyard

Reveal the top X plus one cards of your library and separate them into two piles. An opponent chooses one of those piles. Put that pile into your hand and the other into your graveyard.

Thassa's Oracle

When Thassa's Oracle enters, 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.)

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Curse of Verbosity

Enchant player
Whenever enchanted player is attacked, you draw a card. Each opponent attacking that player does the same.

Spark Double

You may have Spark Double 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.

Glimpse of Freedom

Draw a card.
Escape—{2}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

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.

Campus Guide

When Campus Guide enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Censor

Counter target spell unless its controller pays {1}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Tale's End

Counter target activated ability, triggered ability, or legendary spell.

Kefnet the Mindful

Flying, indestructible
Kefnet the Mindful can't attack or block unless you have seven or more cards in hand.
{3}{U}: Draw a card, then you may return a land you control to its owner's hand.

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Pongify

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

Spellkeeper Weird

{2}, {T}, Sacrifice Spellkeeper Weird: Return target instant or sorcery card from your graveyard to your hand.

Reject

Counter target creature or planeswalker spell unless its controller pays {3}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Talrand, Sky Summoner

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

Negate

Sinister Sabotage

Counter target spell.
Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Scribe of the Mindful

{1}, {T}, Sacrifice Scribe of the Mindful: Return target instant or sorcery card from your graveyard to your hand.

Memory Drain

Medomai's Prophecy

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Scry 2.
II — Choose a card name.
III — When you cast a spell with the chosen name for the first time this turn, draw two cards.
IV — Look at the top card of each player's library.

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.

Ipnu Rivulet

{T}: Add {C}.
{T}, Pay 1 life: Add {U}.
{1}{U}, {T}, Sacrifice a Desert: Target player mills four cards.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Sage's Row Denizen

Whenever another blue creature you control enters, target player mills two cards.

Stern Dismissal

Return target creature or enchantment an opponent controls to its owner's hand.

Diviner's Portent

Roll a d20 and add the number of cards in your hand.
1—14 | Draw X cards.
15+ | Scry X, then draw X cards.

Archmage Emeritus

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

Test of Talents

Counter target instant or sorcery spell. Search its controller's graveyard, hand, and library for any number of cards with the same name as that spell and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Traveler's Amulet

{1}, Sacrifice Traveler's Amulet: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Omen of the Sea

Flash
When Omen of the Sea enters, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: Scry 2.

God-Eternal Kefnet

Flying
You may reveal the first card you draw each turn as you draw it. Whenever you reveal an instant or sorcery card this way, copy that card and you may cast the copy. That copy costs {2} less to cast.
When God-Eternal Kefnet dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Thought Vessel

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

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Capsize

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.)
Return target permanent to its owner's hand.

Ichthyomorphosis

Enchant creature
Enchanted creature loses all abilities and is a blue Fish with base power and toughness 0/1.

Solve the Equation

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

Castle Vantress

Castle Vantress enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Strategic Planning

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Snow Day

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
Draw two cards, then discard a card.

Quench

Counter target spell unless its controller pays {2}.

Kiora Bests the Sea God

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create an 8/8 blue Kraken creature token with hexproof.
II — Tap all nonland permanents target opponent controls. They don't untap during their controller's next untap step.
III — Gain control of target permanent an opponent controls. Untap it.

Thought Scour

Target player mills two cards.
Draw a card.

Serum Visions

Kasmina's Transmutation

Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.

Stealth Mission

Put two +1/+1 counters on target creature you control. That creature can't be blocked this turn.

Reliquary Tower

Supreme Will

Choose one —
• Counter target spell unless its controller pays {3}.
• Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Midnight Clock

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

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Deny the Divine

Counter target creature or enchantment spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Hieroglyphic Illumination

Draw two cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

The Magic Mirror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
You have no maximum hand size.
At the beginning of your upkeep, put a knowledge counter on The Magic Mirror, then draw a card for each knowledge counter on The Magic Mirror.

Psychic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you scry 2.

Drawn from Dreams

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 a random order.

Island

Rapid Hybridization

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

Teachings of the Archaics

If an opponent has more cards in hand than you, draw two cards. Draw three cards instead if an opponent has at least four more cards in hand than you.

Displacement Wave

Return all nonland permanents with mana value X or less to their owners' hands.

Multiple Choice

If X is 1, scry 1, then draw a card.
If X is 2, you may choose a player. They return a creature they control to its owner's hand.
If X is 3, create a 4/4 blue and red Elemental creature token.
If X is 4 or more, do all of the above.

Glasspool Shore

Glasspool Shore enters tapped.
{T}: Add {U}.

Glasspool Mimic

You may have Glasspool Mimic enter as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.