Great Hall of the Biblioplex

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell.
{5}: If this land isn't a creature, it becomes a 2/4 Wizard creature with "Whenever you cast an instant or sorcery spell, this creature gets +1/+0 until end of turn." It's still a land.

Merchant of Venom

Menace
When this creature enters, each player sacrifices a creature of their choice.
Whenever a player sacrifices a permanent, put a +1/+1 counter on this creature.

Killian, Decisive Mentor

Whenever an enchantment you control enters, tap up to one target creature and goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever one or more creatures that are enchanted by an Aura you control attack, draw a card.

Tragedy Feaster

Trample
Ward—Discard a card.
Infusion — At the beginning of your end step, sacrifice a permanent unless you gained life this turn.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Oracle's Gift

Create X 0/0 green and blue Fractal creature tokens, then put X +1/+1 counters on each Fractal you control.

Jadzi, Steward of Fate

Jadzi enters prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)
When Jadzi enters, draw two cards, then discard two cards.

Jadzi, Steward of Fate // Oracle's Gift

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Resonating Lute

Lands you control have "{T}: Add two mana of any one color. Spend this mana only to cast instant and sorcery spells."
{T}: Draw a card. Activate only if you have seven or more cards in your hand.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Mind into Matter

Draw X cards. Then you may put a permanent card with mana value X or less from your hand onto the battlefield tapped.

Awaken the Woods

Create X 1/1 green Forest Dryad land creature tokens. (They're affected by summoning sickness.)

Planar Engineering

Sacrifice two lands. Search your library for four basic land cards, put them onto the battlefield tapped, then shuffle.

Magmablood Archaic

Trample, reach
Converge — This creature enters with a +1/+1 counter on it for each color of mana spent to cast it.
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 until end of turn for each color of mana spent to cast that spell.

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.)

Deathcap Glade

This land enters tapped unless you control two or more other lands.
{T}: Add {B} or {G}.

Deflecting Palm

The next time a source of your choice would deal damage to you this turn, prevent that damage. If damage is prevented this way, Deflecting Palm deals that much damage to that source's controller.

Stock Up

Look at the top five cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Ancestral Recall

Emeritus of Ideation

Flying, ward {2}
This creature enters prepared.
Whenever this creature attacks, you may exile eight cards from your graveyard. If you do, this creature becomes prepared.

Emeritus of Ideation // Ancestral Recall

Exhibition Tidecaller

Opus — Whenever you cast an instant or sorcery spell, target player mills three cards. If five or more mana was spent to cast that spell, that player mills ten cards instead.

Eclipsed Steppe

({T}: Add {W} or {B}.)
This land enters tapped unless you control two or more basic lands.

Pensive Professor

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on this creature, draw a card.

Channel

Until end of turn, any time you could activate a mana ability, you may pay 1 life. If you do, add {C}.

Yavimaya Bloomsage

At the beginning of your end step, put a +1/+1 counter on target creature you control. Then if that creature has power 7 or greater, this creature becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Yavimaya Bloomsage // Channel

Silverquill, the Disputant

Flying, vigilance
Each instant and sorcery spell you cast has casualty 1. (As you cast that spell, you may sacrifice a creature with power 1 or greater. When you do, copy the spell and you may choose new targets for the copy.)

Brain Freeze

Target player mills three cards.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Glimpse of Nature

Whenever you cast a creature spell this turn, draw a card.

Withering Curse

All creatures get -2/-2 until end of turn.
Infusion — If you gained life this turn, destroy all creatures instead.

Conciliator's Duelist

When this creature enters, draw a card. Each player loses 1 life.
Repartee — Whenever you cast an instant or sorcery spell that targets a creature, exile up to one target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Shattered Sanctum

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Erode

Destroy target creature or planeswalker. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.

Living End

Suspend 3—{2}{B}{B}
Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Hop to It

Create three 1/1 white Rabbit creature tokens.

Aziza, Mage Tower Captain

Whenever you cast an instant or sorcery spell, you may tap three untapped creatures you control. If you do, copy that spell. You may choose new targets for the copy.

Changing Loyalty

Flash
Replicate {2} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies. Copies become tokens.)
Enchant creature
When enchanted creature dies, return it to the battlefield under your control.

Lattice Library

This enchantment enters with X study counters on it.
When this enchantment enters and whenever you cast your first spell with {X} in its mana cost each turn, create a 0/0 green and blue Fractal creature token. Put a number of +1/+1 counters on it equal to the number of study counters on this enchantment.

Feral Appetite

Attacking Pests you control get +1/+0 and have deathtouch.
{1}{G}: Exile target card from a graveyard. If a creature card is exiled this way, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Turbulent Moor

({T}: Add {W} or {B}.)
This land enters tapped unless your opponents control eight or more lands.

Sleight of Hand

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Nexus Mentality

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Move all counters from target nonland permanent you control onto another target nonland permanent you control.
• Remove all counters from target nonland permanent you control. Draw a card for each counter removed this way.

Run the Play

Put a +1/+1 counter on each of up to X target creatures. Those creatures gain flying until end of turn. Draw a card.

Striding Shotcaller

Reach
Whenever one or more creatures you control deal combat damage to a player, this creature becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Striding Shotcaller // Run the Play

Quandrix, the Proof

Flying, trample
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Instant and sorcery spells you cast from your hand have cascade.

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Flow State

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. If there is an instant card and a sorcery card in your graveyard, instead put two of them into your hand and the rest on the bottom of your library in any order.