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.

Choking Tethers

Tap up to four target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Choking Tethers, you may tap target creature.

Reckless Scholar

{T}: Target player draws a card, then discards a card.

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Pitiless Vizier

Whenever you cycle or discard a card, Pitiless Vizier gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it. If its toughness is 0 or less, it's still put into its owner's graveyard.)

Jhessian Zombies

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Islandcycling {2}, swampcycling {2} ({2}, Discard this card: Search your library for an Island or Swamp card, reveal it, put it into your hand, then shuffle.)

Dark Withering

Destroy target nonblack creature.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Academy Wall

Defender
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card. This ability triggers only once each turn.

Twisted Abomination

{B}: Regenerate Twisted Abomination.
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Eel Umbra

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +1/+1.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Sift

Rescind

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

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Skirge Familiar

Tolarian Winds

Discard all the cards in your hand, then draw that many cards.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Night's Whisper

Vector Glider

The Modern Age

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Draw a card, then discard a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Modern Age // Vector Glider

Merfolk Looter

Mystic Meditation

Draw three cards. Then discard two cards unless you discard a creature card.

Ghastly Discovery

Draw two cards, then discard a card.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it.)

Dragon Wings

Enchant creature
Enchanted creature has flying.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When a creature with mana value 6 or greater enters the battlefield, you may return Dragon Wings from your graveyard to the battlefield attached to that creature.

Grisly Survivor

Whenever you cycle or discard a card, Grisly Survivor gets +2/+0 until end of turn.

Cephalid Looter

Alms of the Vein

Target opponent loses 3 life and you gain 3 life.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Remote Isle

Remote Isle enters the battlefield tapped.
{T}: Add {U}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Swamp

Trespasser il-Vec

Discard a card: Trespasser il-Vec gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.)
Ulamog's Crusher attacks each combat if able.

Lonely Sandbar

Lonely Sandbar enters the battlefield tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Helm of the Ghastlord

Enchant creature
As long as enchanted creature is blue, it gets +1/+1 and has "Whenever this creature deals damage to an opponent, draw a card."
As long as enchanted creature is black, it gets +1/+1 and has "Whenever this creature deals damage to an opponent, that player discards a card."

Arcane Signet

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

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Traumatic Visions

Counter target spell.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Desert of the Glorified

Desert of the Glorified enters the battlefield tapped.
{T}: Add {B}.
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Cradle of Safety

Flash
Enchant creature you control
When Cradle of Safety enters the battlefield, enchanted creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
Enchanted creature gets +1/+1.

Careful Study

Murderous Compulsion

Destroy target tapped creature.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Grave Scrabbler

Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
When Grave Scrabbler enters the battlefield, if its madness cost was paid, you may return target creature card from a graveyard to its owner's hand.

Brain Gorgers

When you cast this spell, any player may sacrifice a creature. If a player does, counter Brain Gorgers.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Hell Mongrel

Discard a card: Hell Mongrel gets +1/+1 until end of turn.
Madness {2}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Psychotic Haze

Psychotic Haze deals 1 damage to each creature and each player.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Krovikan Sorcerer

{T}, Discard a nonblack card: Draw a card.
{T}, Discard a black card: Draw two cards, then discard one of them.

Dirge of Dread

All creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)
When you cycle Dirge of Dread, you may have target creature gain fear until end of turn.

Thought Courier

Circular Logic

Counter target spell unless its controller pays {1} for each card in your graveyard.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Call to the Netherworld

Return target black creature card from your graveyard to your hand.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Scarab Feast

Exile up to three target cards from a single graveyard.
Cycling {B} ({B}, Discard this card: Draw a card.)

Horror of the Broken Lands

Whenever you cycle or discard another card, Horror of the Broken Lands gets +2/+1 until end of turn.
Cycling {B} ({B}, Discard this card: Draw a card.)

Oblivion Crown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature has "Discard a card: This creature gets +1/+1 until end of turn."

Undertaker

{B}, {T}, Discard a card: Return target creature card from your graveyard to your hand.

Shadowstorm Vizier

Flying
Whenever you cycle or discard a card, Shadowstorm Vizier gets +1/+1 until end of turn.

Rain of Revelation

Polluted Mire

Polluted Mire enters the battlefield tapped.
{T}: Add {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Dimir Infiltrator

Dimir Infiltrator can't be blocked.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Kitchen Imp

Flying, haste
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Ichor Slick

Target creature gets -3/-3 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)
Madness {3}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Waterfront Bouncer

{U}, {T}, Discard a card: Return target creature to its owner's hand.

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Hekma Sentinels

Whenever you cycle or discard a card, Hekma Sentinels gets +1/+1 until end of turn.

Bog Witch

Probe

Kicker {1}{B} (You may pay an additional {1}{B} as you cast this spell.)
Draw three cards, then discard two cards. If this spell was kicked, target player discards two cards.

Expunge

Destroy target nonartifact, nonblack creature. It can't be regenerated.
Cycling {2} ({2}, Discard this card: Draw a card.)

Dark Ritual

Mage's Guile

Target creature gains shroud until end of turn. (It can't be the target of spells or abilities.)
Cycling {U} ({U}, Discard this card: Draw a card.)

Dissolve

Counter target spell. Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Compulsive Research

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Dismal Backwater

Dismal Backwater enters the battlefield tapped.
When Dismal Backwater enters the battlefield, you gain 1 life.
{T}: Add {U} or {B}.

Urborg Syphon-Mage

{2}{B}, {T}, Discard a card: Each other player loses 2 life. You gain life equal to the life lost this way.

Gorgon Recluse

Whenever Gorgon Recluse blocks or becomes blocked by a nonblack creature, destroy that creature at end of combat.
Madness {B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Mind Stone

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

Rousing Read

Enchant creature
When Rousing Read enters the battlefield, draw two cards, then discard a card.
Enchanted creature gets +1/+1 and has flying.

Island

Cabal Initiate

Discard a card: Cabal Initiate gains lifelink until end of turn.
Threshold — Cabal Initiate gets +1/+2 as long as seven or more cards are in your graveyard.

Vorrac Battlehorns

Equipped creature has trample and can't be blocked by more than one creature.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery. This card enters the battlefield unattached and stays on the battlefield if the creature leaves.)

Dragonborn Looter

{1}, {T}: Draw a card, then discard a card.

Catalog

Windcaller Aven

Flying
Cycling {U} ({U}, Discard this card: Draw a card.)
When you cycle Windcaller Aven, target creature gains flying until end of turn.

Fate Transfer

Move all counters from target creature onto another target creature.

Obsessive Search

Draw a card.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Flux

Each player discards any number of cards, then draws that many cards.
Draw a card.

Cunning Survivor

Whenever you cycle or discard a card, Cunning Survivor gets +1/+0 until end of turn and can't be blocked this turn.

Barren Moor

Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Striped Riverwinder

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Cycling {U} ({U}, Discard this card: Draw a card.)

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

Owl Familiar

Flying
When Owl Familiar enters the battlefield, draw a card, then discard a card.

Countervailing Winds

Counter target spell unless its controller pays {1} for each card in your graveyard.
Cycling {2} ({2}, Discard this card: Draw a card.)