As an additional cost to cast this spell, discard X cards.
Look at target opponent's hand and choose X cards from it. That player discards those cards.
--
Arcane Lighthouse
Land
{T}: Add {C}.
{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.
{4}{U}
Arcane Melee
Enchantment
Instant and sorcery spells cost {2} less to cast.
{2}
Arcane Signet
Artifact
{T}: Add one mana of any color in your commander's color identity.
{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
{1}{U/B}{U/B}
Ashiok, Dream Render
Legendary Planeswalker - Ashiok
Spells and abilities your opponents control can't cause their controller to search their library.
-1: Target player mills four cards. Then exile each opponent's graveyard.
L:
5
--
Barren Moor
Land
Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)
{8}{R}
Blasphemous Act
Sorcery
This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.
--
Boseiju, Who Shelters All
Legendary Land
Boseiju, Who Shelters All enters the battlefield tapped.
{T}, Pay 2 life: Add {C}. If that mana is spent on an instant or sorcery spell, that spell can't be countered.
{U}
Brainstorm
Instant
Draw three cards, then put two cards from your hand on top of your library in any order.
{1}{B}
Cabal Ritual
Instant
Add {B}{B}{B}.
Threshold -- Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.
{1}{U}{U}
Callow Jushi
Creature - Human Wizard
Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Callow Jushi.
At the beginning of the end step, if there are two or more ki counters on Callow Jushi, you may flip it.
2 /
2
--
Jaraku the Interloper
Legendary Creature - Spirit
Remove a ki counter from Jaraku the Interloper: Counter target spell unless its controller pays {2}.
2 /
2
{5}{R}
Charmbreaker Devils
Creature - Devil
At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, Charmbreaker Devils gets +4/+0 until end of turn.
4 /
4
--
Clearwater Pathway
Land
{T}: Add {U}.
--
Murkwater Pathway
Land
{T}: Add {B}.
{3}{U}{U}
Cloudhoof Kirin
Legendary Creature - Kirin Spirit
Flying
Whenever you cast a Spirit or Arcane spell, you may have target player mill X cards, where X is that spell's mana value.
4 /
4
--
Command Tower
Land
{T}: Add one mana of any color in your commander's color identity.
{U}{U}
Counterspell
Instant
Counter target spell.
--
Crumbling Necropolis
Land
Crumbling Necropolis enters the battlefield tapped.
{T}: Add {U}, {B}, or {R}.
{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
{1}{U}
Cyclonic Rift
Instant
Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")
{1}{U}
Dampen Thought
Instant - Arcane
Target player mills four cards.
Splice onto Arcane {1}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{3}{B}{B}
Dark Petition
Sorcery
Search your library for a card, put that card into your hand, then shuffle.
Spell mastery -- If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.
{B}
Dark Ritual
Instant
Add {B}{B}{B}.
{1}{R}
Desperate Ritual
Instant - Arcane
Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{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}{R}
Dockside Extortionist
Creature - Goblin Pirate
When Dockside Extortionist enters the battlefield, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")
1 /
2
{2}
Dowsing Dagger
Artifact - Equipment
When Dowsing Dagger enters the battlefield, target opponent creates two 0/2 green Plant creature tokens with defender.
Equipped creature gets +2/+1.
Whenever equipped creature deals combat damage to a player, you may transform Dowsing Dagger.
Equip {2}
--
Lost Vale
Land
(Transforms from Dowsing Dagger.)
{T}: Add three mana of any one color.
--
Dragonskull Summit
Land
Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.
--
Dreadship Reef
Land
{T}: Add {C}.
{1}, {T}: Put a storage counter on Dreadship Reef.
{1}, Remove X storage counters from Dreadship Reef: Add X mana in any combination of {U} and/or {B}.
--
Drowned Catacomb
Land
Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.
{2}{U}
Eerie Procession
Sorcery - Arcane
Search your library for an Arcane card, reveal that card, put it into your hand, then shuffle.
--
Evermind
Instant - Arcane
(Nonexistent mana costs can't be paid.)
Draw a card.
Splice onto Arcane {1}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{U/R}{U/R}{ // }{X}{U}{U}{R}{R}
Expansion // Explosion
Instant // Instant
Copy target instant or sorcery spell with mana value 4 or less. You may choose new targets for the copy.
Explosion deals X damage to any target. Target player draws X cards.
{2}
Fellwar Stone
Artifact
{T}: Add one mana of any color that a land an opponent controls could produce.
--
Forbidden Orchard
Land
{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.
{2}{U}
Frantic Search
Instant
Draw two cards, then discard two cards. Untap up to three lands.
{5}
Gilded Lotus
Artifact
{T}: Add three mana of any one color.
{1}{R}
Glacial Ray
Instant - Arcane
Glacial Ray deals 2 damage to any target.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{U}{R}
Goblin Electromancer
Creature - Goblin Wizard
Instant and sorcery spells you cast cost {1} less to cast.
2 /
2
{4}
Golden Guardian
Artifact Creature - Golem
Defender
{2}: Golden Guardian fights another target creature you control. When Golden Guardian dies this turn, return it to the battlefield transformed under your control.
4 /
4
--
Gold-Forge Garrison
Land
(Transforms from Golden Guardian.)
{T}: Add two mana of any one color.
{4}, {T}: Create a 4/4 colorless Golem artifact creature token.
4 /
4
{1}{U}
Guardian of Solitude
Creature - Spirit
Whenever you cast a Spirit or Arcane spell, target creature gains flying until end of turn.
1 /
2
{2}{R}
Guttersnipe
Creature - Goblin Shaman
Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.
2 /
2
{R}{R}
Increasing Vengeance
Instant
Copy target instant or sorcery spell you control. If this spell was cast from a graveyard, copy that spell twice instead. You may choose new targets for the copies.
Flashback {3}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)
{2}{B}{B}
Infernal Kirin
Legendary Creature - Kirin Spirit
Flying
Whenever you cast a Spirit or Arcane spell, target player reveals their hand and discards all cards with that spell's mana value.
3 /
3
{R}
Into the Fray
Instant - Arcane
Target creature attacks this turn if able.
Splice onto Arcane {R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{3}{R}
Ire of Kaminari
Instant - Arcane
Ire of Kaminari deals damage to any target equal to the number of Arcane cards in your graveyard.
--
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}.)
{2}
Isochron Scepter
Artifact
Imprint -- When Isochron Scepter enters the battlefield, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
{3}{U}
Jace's Sanctum
Enchantment
Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)
{1}{U}{B}{R}
Kess, Dissident Mage
Legendary Creature - Human Wizard
Flying
Once during each of your turns, you may cast an instant or sorcery spell from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead.
3 /
4
--
Lonely Sandbar
Land
Lonely Sandbar enters the battlefield tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)
{3}
Long-Forgotten Gohei
Artifact
Arcane spells you cast cost {1} less to cast.
Spirit creatures you control get +1/+1.
--
Luxury Suite
Land
Luxury Suite enters the battlefield tapped unless you have two or more opponents.
{T}: Add {B} or {R}.
{0}
Mana Crypt
Artifact
At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.
{U}{U}
Mana Drain
Instant
Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.
{4}{U}{R}
Melek, Izzet Paragon
Legendary Creature - Weird Wizard
Play with the top card of your library revealed.
You may cast instant and sorcery spells from the top of your library.
Whenever you cast an instant or sorcery spell from your library, copy it. You may choose new targets for the copy.
2 /
4
{2}{U}{R}
Mizzix of the Izmagnus
Legendary Creature - Goblin Wizard
Whenever you cast an instant or sorcery spell with mana value greater than the number of experience counters you have, you get an experience counter.
Instant and sorcery spells you cast cost {1} less to cast for each experience counter you have.
2 /
2
--
Morphic Pool
Land
Morphic Pool enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {B}.
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
{3}{U}
Murmuring Mystic
Creature - Human Wizard
Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.
1 /
5
{3}{U}
Mystic Retrieval
Sorcery
Return target instant or sorcery card from your graveyard to your hand.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)
{U}
Mystical Tutor
Instant
Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.
{1}{B}
Nightscape Familiar
Creature - Zombie
Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.
1 /
1
{3}{R}{R}
Ore Gorger
Creature - Spirit
Whenever you cast a Spirit or Arcane spell, you may destroy target nonbasic land.
3 /
1
{U}{U}
Power Artifact
Enchantment - Aura
Enchant artifact
Enchanted artifact's activated abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{4}
Primal Amulet
Artifact
Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, put a charge counter on Primal Amulet. Then if there are four or more charge counters on it, you may remove those counters and transform it.
--
Primal Wellspring
Land
(Transforms from Primal Amulet.)
{T}: Add one mana of any color. When that mana is spent to cast an instant or sorcery spell, copy that spell and you may choose new targets for the copy.
{1}{U}
Psychic Puppetry
Instant - Arcane
You may tap or untap target permanent.
Splice onto Arcane {U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{2}{U}{R}
Ral, Storm Conduit
Legendary Planeswalker - Ral
Whenever you cast or copy an instant or sorcery spell, Ral, Storm Conduit deals 1 damage to target opponent or planeswalker.
+2: Scry 1.
-2: When you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
L:
4
--
Riverglide Pathway
Land
{T}: Add {U}.
--
Lavaglide Pathway
Land
{T}: Add {R}.
{3}{U}
Shifting Borders
Instant - Arcane
Exchange control of two target lands.
Splice onto Arcane {3}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{1}
Sol Ring
Artifact
{T}: Add {C}{C}.
{1}{B}
Soulless Revival
Instant - Arcane
Return target creature card from your graveyard to your hand.
Splice onto Arcane {1}{B} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
{2}{U}
Spellseeker
Creature - Human Wizard
When Spellseeker enters the battlefield, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.
1 /
1
--
Sulfur Falls
Land
Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.
--
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}.)
{U}
Swan Song
Instant
Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.
{2}{U}{U}
Talrand, Sky Summoner
Legendary Creature - Merfolk Wizard
Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.
2 /
2
{3}{U}{U}
Teller of Tales
Creature - Spirit
Flying
Whenever you cast a Spirit or Arcane spell, you may tap or untap target creature.
3 /
3
{4}{U}
The Mirari Conjecture
Enchantment - Saga
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I -- Return target instant card from your graveyard to your hand.
II -- Return target sorcery card from your graveyard to your hand.
III -- Until end of turn, whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.
{4}{U}{R}
Thousand-Year Storm
Enchantment
Whenever you cast an instant or sorcery spell, copy it for each other instant and sorcery spell you've cast before it this turn. You may choose new targets for the copies.
{4}{R}
Through the Breach
Instant - Arcane
You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice that creature at the beginning of the next end step.
Splice onto Arcane {2}{R}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)
--
Training Center
Land
Training Center enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {R}.
{3}
Twinning Staff
Artifact
If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy.
{7}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{1}{R}
Young Pyromancer
Creature - Human Shaman
Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.