Draw cards equal to the number of cards in your hand, then discard a card for each card drawn this way.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)
{2}{U}{U}
Archaeomancer
Creature - Human Wizard
When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.
1 /
2
{U}{B}
Baleful Strix
Artifact Creature - Bird
Flying, deathtouch
When Baleful Strix enters the battlefield, draw a card.
1 /
1
--
Barren Moor
Land
Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)
{3}{B}{B}
Beacon of Unrest
Sorcery
Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.
--
Blighted Fen
Land
{T}: Add {C}.
{4}{B}, {T}, Sacrifice Blighted Fen: Target opponent sacrifices a creature.
{4}{U}{U}{U}
Chancellor of the Spires
Creature - Phyrexian Sphinx
You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, each opponent mills seven cards.
Flying
When Chancellor of the Spires enters the battlefield, you may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.
5 /
7
{2}{U}
Chasm Skulker
Creature - Squid Horror
Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)
1 /
1
--
Choked Estuary
Land
As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped.
{T}: Add {U} or {B}.
--
Command Tower
Land
{T}: Add one mana of any color in your commander's color identity.
{3}{U}{B}
Consuming Aberration
Creature - Horror
Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.
* /
*
{4}{U}{U}
Crush of Tentacles
Sorcery
Surge {3}{U}{U} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Return all nonland permanents to their owners' hands. If this spell's surge cost was paid, create an 8/8 blue Octopus creature token.
{1}{U}
Curious Homunculus
Creature - Homunculus
{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.
At the beginning of your upkeep, if there are three or more instant and/or sorcery cards in your graveyard, transform Curious Homunculus.
1 /
1
--
Voracious Reader
Creature - Eldrazi Homunculus
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.
1 /
1
{2}{U}
Curse of the Bloody Tome
Enchantment - Aura Curse
Enchant player
At the beginning of enchanted player's upkeep, that player mills two cards.
--
Darkwater Catacombs
Land
{1}, {T}: Add {U}{B}.
{3}
Dimir Cluestone
Artifact
{T}: Add {U} or {B}.
{U}{B}, {T}, Sacrifice Dimir Cluestone: Draw a card.
{2}
Dimir Signet
Artifact
{1}, {T}: Add {U}{B}.
--
Dismal Backwater
Land
Dismal Backwater enters the battlefield tapped.
When Dismal Backwater enters the battlefield, you gain 1 life.
{T}: Add {U} or {B}.
{3}{U}{U}
Docent of Perfection
Creature - Insect Horror
Flying
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token. Then if you control three or more Wizards, transform Docent of Perfection.
5 /
4
--
Final Iteration
Creature - Eldrazi Insect
Flying
Wizards you control get +2/+1 and have flying.
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token.
5 /
4
{1}{U}
Dreamscape Artist
Creature - Human Spellshaper
{2}{U}, {T}, Discard a card, Sacrifice a land: Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.
1 /
1
{6}
Dreamstone Hedron
Artifact
{T}: Add {C}{C}{C}.
{3}, {T}, Sacrifice Dreamstone Hedron: Draw three cards.
{2}{U}
Ever-Watching Threshold
Enchantment
Whenever an opponent attacks, if they attacked you and/or a planeswalker you control, draw a card.
--
Evolving Wilds
Land
{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{3}{U}{B}
Extract from Darkness
Sorcery
Each player mills two cards. Then you put a creature card from a graveyard onto the battlefield under your control.
{U}{B}
Fathom Feeder
Creature - Eldrazi Drone
Devoid (This card has no color.)
Deathtouch
Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)
{3}{U}{B}: Draw a card. Each opponent exiles the top card of their library.
1 /
1
--
Fetid Pools
Land - Island Swamp
({T}: Add {U} or {B}.)
Fetid Pools enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)
{5}{U}{U}
Fleet Swallower
Creature - Fish
Whenever Fleet Swallower attacks, target player mills half their library, rounded up.
6 /
6
{2}{U}
Fraying Sanity
Enchantment - Aura Curse
Enchant player
At the beginning of each end step, enchanted player mills X cards, where X is the number of cards put into their graveyard from anywhere this turn.
{4}
Grimoire of the Dead
Legendary Artifact
{1}, {T}, Discard a card: Put a study counter on Grimoire of the Dead.
{T}, Remove three study counters from Grimoire of the Dead and sacrifice it: Put all creature cards from all graveyards onto the battlefield under your control. They're black Zombies in addition to their other colors and types.
--
Grixis Panorama
Land
{T}: Add {C}.
{1}, {T}, Sacrifice Grixis Panorama: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.
{3}{B}{B}
Guiltfeeder
Creature - Horror
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Guiltfeeder attacks and isn't blocked, defending player loses 1 life for each card in their graveyard.
0 /
4
{1}{B}{B}
Hero's Downfall
Instant
Destroy target creature or planeswalker.
{2}{U}{U}
Induce Paranoia
Instant
Counter target spell. If {B} was spent to cast this spell, that spell's controller mills X cards, where X is the spell's mana value.
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Jwar Isle Refuge
Land
Jwar Isle Refuge enters the battlefield tapped.
When Jwar Isle Refuge enters the battlefield, you gain 1 life.
{T}: Add {U} or {B}.
{U}{U}{B}{B}
Lazav, Dimir Mastermind
Legendary Creature - Shapeshifter
Hexproof
Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav, Dimir Mastermind become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.
3 /
3
{1}
Library of Leng
Artifact
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.
{4}{B}{B}
Life's Finale
Sorcery
Destroy all creatures, then search target opponent's library for up to three creature cards and put them into their graveyard. Then that player shuffles.
{4}{U}{B}
Lochmere Serpent
Creature - Serpent
Flash
{U}, Sacrifice an Island: Lochmere Serpent can't be blocked this turn.
{B}, Sacrifice a Swamp: You gain 1 life and draw a card.
{U}{B}: Exile five target cards from an opponent's graveyard. Return Lochmere Serpent from your graveyard to your hand. Activate only as a sorcery.
7 /
7
--
Lonely Sandbar
Land
Lonely Sandbar enters the battlefield tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)
{5}{U}{U}{U}
Lorthos, the Tidemaker
Legendary Creature - Octopus
Whenever Lorthos, the Tidemaker attacks, you may pay {8}. If you do, tap up to eight target permanents. Those permanents don't untap during their controllers' next untap steps.
8 /
8
{1}{U}{U}
Memory Erosion
Enchantment
Whenever an opponent casts a spell, that player mills two cards.
{U/B}{U/B}{U/B}{U/B}
Memory Plunder
Instant
You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.
{2}
Mind Stone
Artifact
{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.
{2}
Mindcrank
Artifact
Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)
{5}{U}{B}{B}
Mindleech Mass
Creature - Horror
Trample
Whenever Mindleech Mass deals combat damage to a player, you may look at that player's hand. If you do, you may cast a spell from among those cards without paying its mana cost.
6 /
6
{3}{U}{B}
Mirko Vosk, Mind Drinker
Legendary Creature - Vampire
Flying
Whenever Mirko Vosk, Mind Drinker deals combat damage to a player, that player reveals cards from the top of their library until they reveal four land cards, then puts those cards into their graveyard.
2 /
4
--
Morphic Pool
Land
Morphic Pool enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {B}.
{3}{U}{U}
Mystic Confluence
Instant
Choose three. You may choose the same mode more than once.
• Counter target spell unless its controller pays {3}.
• Return target creature to its owner's hand.
• Draw a card.
--
Mystifying Maze
Land
{T}: Add {C}.
{4}, {T}: Exile target attacking creature an opponent controls. At the beginning of the next end step, return it to the battlefield tapped under its owner's control.
{4}{B}{B}{B}
Necromantic Selection
Sorcery
Destroy all creatures, then return a creature card put into a graveyard this way to the battlefield under your control. It's a black Zombie in addition to its other colors and types. Exile Necromantic Selection.
{2}{B}{B}
Necrotic Ooze
Creature - Ooze
As long as Necrotic Ooze is on the battlefield, it has all activated abilities of all creature cards in all graveyards.
4 /
3
{3}{U}{B}
Nemesis of Reason
Creature - Leviathan Horror
Whenever Nemesis of Reason attacks, defending player mills ten cards.
3 /
7
{4}
Nevinyrral's Disk
Artifact
Nevinyrral's Disk enters the battlefield tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.
{1}{B}{B}
Nighthowler
Enchantment Creature - Horror
Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.
0 /
0
{U/B}{U/B}{U/B}
Nightveil Specter
Creature - Specter
Flying
Whenever Nightveil Specter deals combat damage to a player, that player exiles the top card of their library.
You may play lands and cast spells from among cards exiled with Nightveil Specter.
2 /
3
{3}{U}{B}
Phenax, God of Deception
Legendary Enchantment Creature - God
Indestructible
As long as your devotion to blue and black is less than seven, Phenax isn't a creature.
Creatures you control have "{T}: Target player mills X cards, where X is this creature's toughness."
4 /
7
{2}{B}
Read the Bones
Sorcery
Scry 2, then draw two cards. You lose 2 life.
--
Reliquary Tower
Land
You have no maximum hand size.
{T}: Add {C}.
--
Rogue's Passage
Land
{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.
{1}{B}{B}
Ruinous Path
Sorcery
Destroy target creature or planeswalker.
Awaken 4--{5}{B}{B} (If you cast this spell for {5}{B}{B}, also put four +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)
{2}
Sapphire Medallion
Artifact
Blue spells you cast cost {1} less to cast.
--
Sea Gate Wreckage
Land
{T}: Add {C}. ({C} represents colorless mana.)
{2}{C}, {T}: Draw a card. Activate only if you have no cards in hand.
{5}
Seal of the Guildpact
Artifact
As Seal of the Guildpact enters the battlefield, choose two colors.
Each spell you cast costs {1} less to cast for each of the chosen colors it is.
{5}{B}{B}
Sepulchral Primordial
Creature - Avatar
Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
When Sepulchral Primordial enters the battlefield, for each opponent, you may put up to one target creature card from that player's graveyard onto the battlefield under your control.
5 /
4
{3}{B}
Sewer Nemesis
Creature - Horror
As Sewer Nemesis enters the battlefield, choose a player.
Sewer Nemesis's power and toughness are each equal to the number of cards in the chosen player's graveyard.
Whenever the chosen player casts a spell, that player mills a card.
* /
*
{1}{U}{B}
Shadowmage Infiltrator
Creature - Human Wizard
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Shadowmage Infiltrator deals combat damage to a player, you may draw a card.
1 /
3
{4}{U}{B}
Sire of Stagnation
Creature - Eldrazi
Devoid (This card has no color.)
Whenever a land enters the battlefield under an opponent's control, that player exiles the top two cards of their library and you draw two cards.
5 /
7
{1}
Sol Ring
Artifact
{T}: Add {C}{C}.
{2}{U}{U}
Startled Awake
Sorcery
Target opponent mills thirteen cards.
{3}{U}{U}: Put Startled Awake from your graveyard onto the battlefield transformed. Activate only as a sorcery.
--
Persistent Nightmare
Creature - Nightmare
Skulk (This creature can't be blocked by creatures with greater power.)
When Persistent Nightmare deals combat damage to a player, return it to its owner's hand.
{3}{U}{U}
Stitcher Geralf
Legendary Creature - Human Wizard
{2}{U}, {T}: Each player mills three cards. Exile up to two creature cards put into graveyards this way. Create an X/X blue Zombie creature token, where X is the total power of the cards exiled this way.
3 /
4
--
Sunken Hollow
Land - Island Swamp
({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Temple of the False God
Land
{T}: Add {C}{C}. Activate only if you control five or more lands.
--
Terramorphic Expanse
Land
{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{1}{U}
Thing in the Ice
Creature - Horror
Defender
Thing in the Ice enters the battlefield with four ice counters on it.
Whenever you cast an instant or sorcery spell, remove an ice counter from Thing in the Ice. Then if it has no ice counters on it, transform it.
0 /
4
--
Awoken Horror
Creature - Kraken Horror
When this creature transforms into Awoken Horror, return all non-Horror creatures to their owners' hands.
0 /
4
{2}{U}
Trail of Evidence
Enchantment
Whenever you cast an instant or sorcery spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
{3}{U}{U}
Traumatize
Sorcery
Target player mills half their library, rounded down.
--
Underground River
Land
{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.
--
Vivid Creek
Land
Vivid Creek enters the battlefield tapped with two charge counters on it.
{T}: Add {U}.
{T}, Remove a charge counter from Vivid Creek: Add one mana of any color.
{4}{B}{B}
Void Maw
Creature - Horror
Trample
If another creature would die, exile it instead.
Put a card exiled with Void Maw into its owner's graveyard: Void Maw gets +2/+2 until end of turn.
Islandwalk, swampwalk (This creature can't be blocked as long as defending player controls an Island or a Swamp.)
Whenever Wrexial, the Risen Deep deals combat damage to a player, you may cast target instant or sorcery card from that player's graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.