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.

Sorcerer's Strongbox

{2}, {T}: Flip a coin. If you win the flip, sacrifice Sorcerer's Strongbox and draw three cards.

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.

Jace, Arcane Strategist

Whenever you draw your second card each turn, put a +1/+1 counter on target creature you control.
+1: Draw a card.
−7: Creatures you control can't be blocked this turn.

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.)

Volatile Rig

Trample
Volatile Rig attacks each combat if able.
Whenever Volatile Rig is dealt damage, flip a coin. If you lose the flip, sacrifice Volatile Rig.
When Volatile Rig dies, flip a coin. If you lose the flip, it deals 4 damage to each creature and each player.

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.

Goblin Lyre

Sacrifice Goblin Lyre: Flip a coin. If you win the flip, Goblin Lyre deals damage to target opponent or planeswalker equal to the number of creatures you control. If you lose the flip, Goblin Lyre deals damage to you equal to the number of creatures that opponent or that planeswalker's controller controls.

Creepy Doll

Indestructible
Whenever Creepy Doll deals combat damage to a creature, flip a coin. If you win the flip, destroy that creature.

Thopter Mechanic

Whenever you draw your second card each turn, put a +1/+1 counter on Thopter Mechanic.
When Thopter Mechanic dies, create a 1/1 colorless Thopter artifact creature token with flying.

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.

Mantle of Tides

Equipped creature gets +1/+2.
Whenever you draw your second card each turn, attach Mantle of Tides to target creature you control.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Wirefly Hive

{3}, {T}: Flip a coin. If you win the flip, create a 2/2 colorless Insect artifact creature token with flying named Wirefly. If you lose the flip, destroy all permanents named Wirefly.

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.

Descendant of Soramaro

{1}{U}: Look at the top X cards of your library, where X is the number of cards in your hand, then put them back in any order.

Boompile

{T}: Flip a coin. If you win the flip, destroy all nonland permanents.

Wiretapping

Hideaway 5 (When this enchantment enters, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Whenever you draw your first card during each of your draw steps, draw a card. Then if you have nine or more cards in hand, you may play the exiled card without paying its mana cost.

Meishin, the Mind Cage

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

Mystic Skyfish

Whenever you draw your second card each turn, Mystic Skyfish gains flying until end of turn.

Alandra, Sky Dreamer

Whenever you draw your second card each turn, create a 2/2 blue Drake creature token with flying.
Whenever you draw your fifth card each turn, Alandra, Sky Dreamer and Drakes you control each get +X/+X until end of turn, where X is the number of cards in your hand.

Sea Gate, Reborn

As Sea Gate, Reborn enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sea Gate Restoration

Draw cards equal to the number of cards in your hand plus one. You have no maximum hand size for the rest of the game.

Sea Gate Restoration // Sea Gate, Reborn

Bottle of Suleiman

{1}, Sacrifice Bottle of Suleiman: Flip a coin. If you win the flip, create a 5/5 colorless Djinn artifact creature token with flying. If you lose the flip, Bottle of Suleiman deals 5 damage to you.

Zndrsplt, Eye of Wisdom

Partner with Okaun, Eye of Chaos (When this creature enters, target player may put Okaun into their hand from their library, then shuffle.)
At the beginning of combat on your turn, flip a coin until you lose a flip.
Whenever a player wins a coin flip, draw a card.

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.

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.

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}

Syr Elenora, the Discerning

Syr Elenora, the Discerning's power is equal to the number of cards in your hand.
When Syr Elenora enters, draw a card.
Spells your opponents cast that target Syr Elenora cost {2} more to cast.

Ivory Tower

At the beginning of your upkeep, you gain X life, where X is the number of cards in your hand minus 4.

Mordenkainen

+2: Draw two cards, then put a card from your hand on the bottom of your library.
−2: Create a blue Dog Illusion creature token with "This creature's power and toughness are each equal to twice the number of cards in your hand."
−10: Exchange your hand and library, then shuffle. You get an emblem with "You have no maximum hand size."

Enter the Infinite

Draw cards equal to the number of cards in your library, then put a card from your hand on top of your library. You have no maximum hand size until your next turn.

Island

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.)

Oboro Envoy

Flying
{2}, Return a land you control to its owner's hand: Target creature gets -X/-0 until end of turn, where X is the number of cards in your hand.

Tomoya the Revealer

{3}{U}{U}, {T}: Target player draws X cards, where X is the number of cards in your hand.

Jushi Apprentice

{2}{U}, {T}: Draw a card. If you have nine or more cards in hand, flip Jushi Apprentice.

Jushi Apprentice // Tomoya the Revealer

Steelgaze Griffin

Flying
Whenever you draw your second card each turn, Steelgaze Griffin gets +2/+0 until end of turn.

Lat-Nam Adept

Whenever you draw your second card each turn, put a +1/+1 counter on Lat-Nam Adept.

Crooked Scales

{4}, {T}: Flip a coin. If you win the flip, destroy target creature an opponent controls. If you lose the flip, destroy target creature you control unless you pay {3} and repeat this process.

Ethereal Investigator

Flying
When Ethereal Investigator enters, investigate X times, where X is the number of opponents you have. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you draw your second card each turn, create a 1/1 white Spirit creature token with flying.

Krark's Thumb

If you would flip a coin, instead flip two coins and ignore one.

B.O.B. (Bevy of Beebles)

As B.O.B. enters, create four 1/1 blue Beeble creature tokens.
The number of loyalty counters on B.O.B. is equal to the number of Beebles you control. (Create or sacrifice Beebles whenever B.O.B. gains or loses loyalty.)
+1: Up to X target Beebles can't be blocked this turn, where X is the number of cards in your hand.
−1: Draw a card.

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.