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.

The Grim Captain's Locker

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Until end of turn, each creature card in your graveyard gains "Escape—{3}{B}, Exile four other cards from your graveyard." (You may cast a card with escape from your graveyard for its escape cost.)

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Backdraft Hellkite

Flying
Whenever Backdraft Hellkite attacks, each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Return the Past

During your turn, each instant and sorcery card in your graveyard has flashback. Its flashback cost is equal to its mana cost.

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Calibrated Blast

Reveal cards from the top of your library until you reveal a nonland card. Put the revealed cards on the bottom of your library in a random order. When you reveal a nonland card this way, Calibrated Blast deals damage equal to that card's mana value to any target.
Flashback {3}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mortuary Mire

Mortuary Mire enters tapped.
When Mortuary Mire enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Sequestered Stash

{T}: Add {C}.
{4}, {T}, Sacrifice Sequestered Stash: Mill five cards. Then you may put an artifact card from your graveyard on top of your library.

Nephalia Academy

If a spell or ability an opponent controls causes you to discard a card, you may reveal that card and put it on top of your library instead of putting it anywhere else.
{T}: Add {C}.

Forever Young

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Rage Reflection

Creatures you control have double strike.

Sanguine Spy

Menace, lifelink
{1}, Sacrifice another creature: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
At the beginning of your end step, if there are five or more mana values among cards in your graveyard, you may pay 2 life. If you do, draw a card.

Bone Harvest

Put any number of target creature cards from your graveyard on top of your library.
Draw a card at the beginning of the next turn's upkeep.

Dead Reckoning

You may put target creature card from your graveyard on top of your library. If you do, Dead Reckoning deals damage equal to that card's power to target creature.

Rowan's Grim Search

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
If this spell was bargained, look at the top four cards of your library, then put up to two of them back on top of your library in any order and the rest into your graveyard.
You draw two cards and you lose 2 life.

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Army of the Damned

Create thirteen tapped 2/2 black Zombie creature tokens.
Flashback {7}{B}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Clandestine Meddler

When Clandestine Meddler enters, suspect up to one other target creature you control. (A suspected creature has menace and can't block.)
Whenever one or more suspected creatures you control attack, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Lizard Blades

Double strike
Equipped creature has double strike.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Biblioplex Assistant

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

Past in Flames

Each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mortuary

Whenever a creature is put into your graveyard from the battlefield, put that card on top of your library.

Orcish Librarian

{R}, {T}: Look at the top eight cards of your library. Exile four of them at random, then put the rest on top of your library in any order.

Leashling

Put a card from your hand on top of your library: Return Leashling to its owner's hand.

Eye of Duskmantle

Flying, lifelink
You may play lands and cast spells from among cards in your graveyard you've surveilled this turn. If you cast a spell this way, you pay life equal to its mana value rather than paying its mana cost.

Footbottom Feast

Brainstone

{2}, {T}, Sacrifice Brainstone: Draw three cards, then put two cards from your hand on top of your library in any order.

Eat to Extinction

Exile target creature or planeswalker. Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)