Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Dark Apostle

Gift of Chaos — {3}, {T}: The next noncreature spell you cast this turn has cascade. (When you cast that 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.)

Book Devourer

Trample
Whenever Book Devourer deals combat damage to a player, you may discard all the cards in your hand. If you do, draw that many cards.

Mountain

Audacious Reshapers

{T}, Sacrifice an artifact: Reveal cards from the top of your library until you reveal an artifact card. Put that card onto the battlefield and the rest on the bottom of your library in a random order. Audacious Reshapers deals damage to you equal to the number of cards revealed this way.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

The Underworld Cookbook

{T}, Discard a card: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{4}, {T}, Sacrifice The Underworld Cookbook: Return target creature card from your graveyard to your hand.

Skullknocker Ogre

Whenever Skullknocker Ogre deals damage to an opponent, that player discards a card at random. If the player does, they draw a card.

Shattering Spree

Replicate {R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Destroy target artifact.

Manic Vandal

When Manic Vandal enters, destroy target artifact.

Mindsparker

First strike (This creature deals combat damage before creatures without first strike.)
Whenever an opponent casts a white or blue instant or sorcery spell, Mindsparker deals 2 damage to that player.

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Conspiracy Theorist

Whenever Conspiracy Theorist attacks, you may pay {1} and discard a card. If you do, draw a card.
Whenever you discard one or more nonland cards, you may exile one of them from your graveyard. If you do, you may cast it this turn.

Tome Shredder

Haste
{T}, Exile an instant or sorcery card from your graveyard: Put a +1/+1 counter on Tome Shredder.

Dismissive Pyromancer

{R}, {T}, Discard a card: Draw a card.
{2}{R}, {T}, Sacrifice Dismissive Pyromancer: It deals 4 damage to target creature.

Mishra's Research Desk

{1}, {T}, Sacrifice Mishra's Research Desk: Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.
Unearth {1}{R} ({1}{R}: Return this card from your graveyard to the battlefield. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Rummaging Goblin

Storm Entity

Haste
Storm Entity enters with a +1/+1 counter on it for each other spell cast this turn.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Automatic Librarian

When Automatic Librarian enters, 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.)

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.

Biblioplex Assistant

Flying
When Biblioplex Assistant enters, put up to one target instant or sorcery card from your graveyard on top of your library.

Shiny 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 create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Letter of Acceptance

{T}: Add one mana of any color.
{2}, {T}, Sacrifice Letter of Acceptance: Draw a card.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Revolutionist

When Revolutionist enters, return target instant or sorcery card from your graveyard to your hand.
Madness {3}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Faithless Salvaging

Discard a card, then draw a card.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Goblin Lore

Draw four cards, then discard three cards at random.

Tome of Legends

Tome of Legends enters with a page counter on it.
Whenever your commander enters or attacks, put a page counter on Tome of Legends.
{1}, {T}, Remove a page counter from Tome of Legends: Draw a card.

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

Haggle

You may discard a card. If you do, draw a card. (Then exile this card. You may cast the creature later from exile.)

Merchant of the Vale

Merchant of the Vale // Haggle

Ignacio of Myra's Marvels

As Ignacio of Myra's Marvels enters, choose armor, blood, book, bottle, fang, fire, scroll, spear, sword, or water.
Whenever you cast a spell with the chosen object in its art, create two Treasure tokens.
Partner (You can have two commanders if both have partner.)