Tidespout Tyrant

Flying
Whenever you cast a spell, return target permanent to its owner's hand.

Toothy, Imaginary Friend

Partner with Pir, Imaginative Rascal (When this creature enters, target player may put Pir into their hand from their library, then shuffle.)
Whenever you draw a card, put a +1/+1 counter on Toothy, Imaginary Friend.
When Toothy leaves the battlefield, draw a card for each +1/+1 counter on it.

Reliquary Tower

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

Ominous Seas

Whenever you draw a card, put a foreshadow counter on Ominous Seas.
Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Teferi's Moat

As Teferi's Moat enters, choose a color.
Creatures of the chosen color without flying can't attack you.

Thought Vessel

Faerie Vandal

Flash (You may cast this spell any time you could cast an instant.)
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Faerie Vandal.

Soramaro, First to Dream

Flying
Soramaro, First to Dream's power and toughness are each equal to the number of cards in your hand.
{4}, Return a land you control to its owner's hand: Draw a card.

Hoofprints of the Stag

Whenever you draw a card, you may put a hoofprint counter on Hoofprints of the Stag.
{2}{W}, Remove four hoofprint counters from Hoofprints of the Stag: Create a 4/4 white Elemental creature token with flying. Activate only during your turn.

Hand of Vecna

At the beginning of combat on your turn, equipped creature or a creature you control named Vecna gets +X/+X until end of turn, where X is the number of cards in your hand.
Equip—Pay 1 life for each card in your hand.
Equip {2}

Tameshi, Reality Architect

Whenever one or more noncreature permanents are returned to hand, draw a card. This ability triggers only once each turn.
{X}{W}, Return a land you control to its owner's hand: Return target artifact or enchantment card with mana value X or less from your graveyard to the battlefield. Activate only as a sorcery.

Teferi, Hero of Dominaria

+1: Draw a card. At the beginning of the next end step, untap up to two lands.
−3: Put target nonland permanent into its owner's library third from the top.
−8: You get an emblem with "Whenever you draw a card, exile target permanent an opponent controls."

Curiosity Crafter

Flying
You have no maximum hand size.
Whenever a creature token you control deals combat damage to a player, draw a card.

Meishin, the Mind Cage

All creatures get -X/-0, where X is the number of cards in your hand.

Regress

Return target permanent to its owner's hand.

Minn, Wily Illusionist

Whenever you draw your second card each turn, create a 1/1 blue Illusion creature token with "This creature gets +1/+0 for each other Illusion you control."
Whenever an Illusion you control dies, you may put a permanent card with mana value less than or equal to that creature's power from your hand onto the battlefield.

Deliver

Stand

Prevent the next 2 damage that would be dealt to target creature this turn.

Stand // Deliver

Temporal Adept

{U}{U}{U}, {T}: Return target permanent to its owner's hand.

Surging Aether

Ripple 4 (When you cast this spell, you may reveal the top four cards of your library. You may cast spells with the same name as this spell from among those cards without paying their mana costs. Put the rest on the bottom of your library.)
Return target permanent to its owner's hand.

Rescind

Return target permanent to its owner's hand.
Cycling {2} ({2}, Discard this card: 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.

Ponder

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

Inscription of Insight

Kicker {2}{U}{U}
Choose one. If this spell was kicked, choose any number instead.
• Return up to two target creatures to their owners' hands.
• Scry 2, then draw two cards.
• Target player creates an X/X blue Illusion creature token, where X is the number of cards in their hand.

Oneirophage

Flying
Whenever you draw a card, put a +1/+1 counter on Oneirophage.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

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.)

Arcane Signet

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

Azorius Signet

Consign to Dream

Return target permanent to its owner's hand. If that permanent is red or green, put it on top of its owner's library instead.

Lost in the Mist

Counter target spell. Return target permanent to its owner's hand.

Surgespanner

Whenever Surgespanner becomes tapped, you may pay {1}{U}. If you do, return target permanent to its owner's hand.

Dematerialize

Return target permanent to its owner's hand.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Sturmgeist

Flying
Sturmgeist's power and toughness are each equal to the number of cards in your hand.
Whenever Sturmgeist deals combat damage to a player, draw a card.

Aeon Chronicler

Aeon Chronicler's power and toughness are each equal to the number of cards in your hand.
Suspend X—{X}{3}{U}. X can't be 0.
Whenever a time counter is removed from Aeon Chronicler while it's exiled, draw a card.

Sol Ring

Shabraz, the Skyshark

Partner with Brallin, Skyshark Rider
Flying
Whenever you draw a card, put a +1/+1 counter on Shabraz, the Skyshark and you gain 1 life.
{W/U}: Target Human gains flying until end of turn.

Eye of Nowhere

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

Teferi, Master of Time

You may activate loyalty abilities of Teferi, Master of Time on any player's turn any time you could cast an instant.
+1: Draw a card, then discard a card.
−3: Target creature you don't control phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
−10: Take two extra turns after this one.

Dream Trawler

Flying, lifelink
Whenever you draw a card, Dream Trawler gets +1/+0 until end of turn.
Whenever Dream Trawler attacks, draw a card.
Discard a card: Dream Trawler gains hexproof until end of turn. Tap it.

Nadir Kraken

Whenever you draw a card, you may pay {1}. If you do, put a +1/+1 counter on Nadir Kraken and create a 1/1 blue Tentacle creature token.

Serum Visions

Aether Tradewinds

Return target permanent you control and target permanent you don't control to their owners' hands.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Reality Strobe

Return target permanent to its owner's hand. Exile Reality Strobe with three time counters on it.
Suspend 3—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Wipe Away

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Return target permanent to its owner's hand.

Body of Knowledge

Body of Knowledge's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
Whenever Body of Knowledge is dealt damage, draw that many cards.

Riftwing Cloudskate

Flying
When Riftwing Cloudskate enters, return target permanent to its owner's hand.
Suspend 3—{1}{U} (Rather than cast this card from your hand, you may pay {1}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Heidar, Rimewind Master

{2}, {T}: Return target permanent to its owner's hand. Activate only if you control four or more snow permanents.

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.

Boomerang

Dispersing Orb

{3}{U}, Sacrifice a permanent: Return target permanent to its owner's hand.

Commence the Endgame

This spell can't be countered.
Draw two cards, then amass Zombies X, where X is the number of cards in your hand. (Put X +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Chasm Skulker

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.)

Brainstorm

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