Infernal Plunge

As an additional cost to cast this spell, sacrifice a creature.
Add {R}{R}{R}.

Have

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.

Thermopod

{S}: Thermopod gains haste until end of turn. ({S} can be paid with one mana from a snow source.)
Sacrifice a creature: Add {R}.

Perplex

Counter target spell unless its controller discards their hand.
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.)

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Maestros Theater

When Maestros Theater enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Dispel

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.)

Don't Have

Exhume

Each player puts a creature card from their graveyard onto the battlefield.

Escape Tunnel

{T}, Sacrifice Escape Tunnel: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{T}, Sacrifice Escape Tunnel: Target creature with power 2 or less can't be blocked this turn.

Sleight of Hand

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Pentad Prism

Sunburst (This enters with a charge counter on it for each color of mana spent to cast it.)
Remove a charge counter from Pentad Prism: Add one mana of any color.

Demonic Gifts

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield under its owner's control."

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Drift of Phantasms

Defender (This creature can't attack.)
Flying
Transmute {1}{U}{U} ({1}{U}{U}, 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.)

Great Hall of the Citadel

{T}: Add {C}.
{1}, {T}: Add two mana in any combination of colors. Spend this mana only to cast legendary spells.

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Swamp

Thunderclap

You may sacrifice a Mountain rather than pay this spell's mana cost.
Thunderclap deals 3 damage to target creature.

Dimir Signet

Chromatic Star

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a 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.

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters tapped.

Chromatic Sphere

{1}, {T}, Sacrifice Chromatic Sphere: Add one mana of any color. Draw a card.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Shimmer of Possibility

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.

Erebor Flamesmith

Whenever you cast an instant or sorcery spell, Erebor Flamesmith deals 1 damage to each opponent.

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.)

Treasure Cruise

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Riveteers Overlook

When Riveteers Overlook enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Molten Tributary

({T}: Add {U} or {R}.)
Molten Tributary enters tapped.

Mountain

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Rakdos Signet

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Burnt Offering

As an additional cost to cast this spell, sacrifice a creature.
Add X mana in any combination of {B} and/or {R}, where X is the sacrificed creature's mana value.

Mystical Teachings

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.
Flashback {5}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sulfurous Mire

({T}: Add {B} or {R}.)
Sulfurous Mire enters tapped.

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.)

Preordain

Scry 2, then draw a card. (To 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.)

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, 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.)

Shred Memory

Exile up to four target cards from a single graveyard.
Transmute {1}{B}{B} ({1}{B}{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.)

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Counterspell

Serum Visions

Terminate

Destroy target creature. It can't be regenerated.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Evolving Wilds

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

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Cormela, Glamour Thief

Haste
{1}, {T}: Add {U}{B}{R}. Spend this mana only to cast instant and/or sorcery spells.
When Cormela, Glamour Thief dies, return up to one target instant or sorcery card from your graveyard to your hand.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Terramorphic Expanse

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

Ophidian Eye

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Aether Spellbomb

{U}, Sacrifice Aether Spellbomb: Return target creature to its owner's hand.
{1}, Sacrifice Aether Spellbomb: Draw a card.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Seething Landscape

{T}: Add {C}.
{T}, Sacrifice Seething Landscape: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.
Cycling {U}{B}{R} ({U}{B}{R}, Discard this card: Draw a card.)

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Dizzy Spell

Target creature gets -3/-0 until end of turn.
Transmute {1}{U}{U} ({1}{U}{U}, 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.)

Tandem Lookout

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Tandem Lookout is paired with another creature, each of those creatures has "Whenever this creature deals damage to an opponent, draw a card."

Brainspoil

Destroy target creature that isn't enchanted. It can't be regenerated.
Transmute {1}{B}{B} ({1}{B}{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.)

Izzet Signet

Negate

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Star Compass

Star Compass enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Island

Snapback

You may exile a blue card from your hand rather than pay this spell's mana cost.
Return target creature to its owner's hand.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Arcane Signet

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

Pyromatics

Replicate {1}{R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Pyromatics deals 1 damage to any target.

Dark Ritual

Snap

Return target creature to its owner's hand. Untap up to two lands.

Whispers of the Muse

Buyback {5} (You may pay an additional {5} as you cast this spell. If you do, put this card into your hand as it resolves.)
Draw a card.

Intervene

Counter target spell that targets a creature.

Geothermal Bog

({T}: Add {B} or {R}.)
Geothermal Bog enters tapped.

Ashnod's Altar

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.