Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Wee Dragonauts

Flying
Whenever you cast an instant or sorcery spell, Wee Dragonauts gets +2/+0 until end of turn.

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Sky Diamond

Capsizing Wave

Return target creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Sword Coast Serpent

Sword Coast Serpent can't be blocked as long as you've cast a noncreature spell this turn.

Sword Coast Serpent // Capsizing Wave

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Vodalian Arcanist

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.

Bloodfire Expert

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Pirate's Pillage

Teach by Example

({U/R} can be paid with either {U} or {R}.)
When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Prismari Campus

Prismari Campus enters tapped.
{T}: Add {U} or {R}.
{4}, {T}: Scry 1.

Fall from Favor

Enchant creature
When Fall from Favor enters, tap enchanted creature and you become the monarch.
Enchanted creature doesn't untap during its controller's untap step unless that player is the monarch.

Serum Visions

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

Arcane Signet

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

Firebrand Archer

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

Aven Wind Mage

Flying
Whenever you cast an instant or sorcery spell, Aven Wind Mage gets +1/+1 until end of turn.

Fellwar Stone

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

Thorned Moloch

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Thorned Moloch has first strike as long as it's attacking.

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

Counterspell

Mountain

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Brainstorm

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

Vedalken Blademaster

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.)

Keep Watch

Spectacle Mage

Flying
Instant and sorcery spells you cast with mana value 5 or greater cost {1} less to cast.

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Mana Leak

Counter target spell unless its controller pays {3}.

Seething Song

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

Unwind

Counter target noncreature spell. Untap up to three lands.

Jeskai Windscout

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Niblis of Dusk

Goblin Wizardry

Create two 1/1 red Goblin Wizard creature tokens with prowess. (Whenever you cast a noncreature spell, they get +1/+1 until end of turn.)

Tamiyo's Epiphany

Galvanic Relay

Exile the top card of your library. During your next turn, you may play that card.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Unblinking Observer

{T}: Add {U}. Spend this mana only to pay a disturb cost or cast an instant or sorcery spell.

Jeskai Elder

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Jeskai Elder deals combat damage to a player, you may draw a card. If you do, discard a card.

Volatile Fjord

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

Spell Pierce

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

Secrets of the Key

Investigate. If this spell was cast from a graveyard, investigate twice instead. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Flashback {3}{U}

Pyre Hound

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Pyre Hound.

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Star Compass

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

Temporal Fissure

Return target permanent to its owner's hand.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Cosmotronic Wave

Cosmotronic Wave deals 1 damage to each creature your opponents control. Creatures your opponents control can't block this turn.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Lotus Path Djinn

Fade Away

For each creature, its controller sacrifices a permanent of their choice unless they pay {1}.

Voyage's End

Return target creature to its owner's hand. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Uncovered Clues

Look at the top four cards of your library. You may reveal up to two instant and/or sorcery cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in any order.

Command Tower

Spellweaver Eternal

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)

Lightning Visionary

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Thunder Drake

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on Thunder Drake.

Peek

Look at target player's hand.
Draw a card.

Pyroceratops

Trample
Whenever you cast a noncreature spell, put a +1/+1 counter on Pyroceratops.

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Fall of the Hammer

Target creature you control deals damage equal to its power to another target creature.

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Mage-Ring Bully

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Mage-Ring Bully attacks each combat if able.

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

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.

Desperate Ritual

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.)

Bonder's Ornament

{T}: Add one mana of any color.
{4}, {T}: Each player who controls a permanent named Bonder's Ornament draws a card.

Bloodwater Entity

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Bloodwater Entity enters, you may put target instant or sorcery card from your graveyard on top of your library.

Molten Tributary

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

Karfell Harbinger

{T}: Add {U}. Spend this mana only to foretell a card from your hand or cast an instant or sorcery spell.

Highland Lake

Highland Lake enters tapped.
{T}: Add {U} or {R}.

Sanguinary Mage

Arcbound Tracker

Menace
Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Whenever you cast a spell other than your first spell each turn, put a +1/+1 counter on Arcbound Tracker.

Negate

Riverwheel Aerialists

Trumpet Blast

Attacking creatures get +2/+0 until end of turn.

Snap

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

Whirlwind Adept

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Portent

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.
Draw a card at the beginning of the next turn's upkeep.

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.)

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Battle Hymn

Spellgorger Weird

Whenever you cast a noncreature spell, put a +1/+1 counter on Spellgorger Weird.

Thriving Isle

Thriving Isle enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Unsummon

Return target creature to its owner's hand.

Mistral Singer

Pieces of the Puzzle

Reveal the top five cards of your library. Put up to two instant and/or sorcery cards from among them into your hand and the rest into your graveyard.

Island

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Third Path Iconoclast

Whenever you cast a noncreature spell, create a 1/1 colorless Soldier artifact creature token.

Jeskai Sage

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Jeskai Sage dies, draw a card.

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.

Nimble-Blade Khenra

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Mana Geyser

Add {R} for each tapped land your opponents control.

Elusive Spellfist

Whenever you cast a noncreature spell, Elusive Spellfist gets +1/+0 until end of turn and can't be blocked this turn.

Rolling Thunder

Rolling Thunder deals X damage divided as you choose among any number of targets.

Into the Roil

Mischievous Chimera

Flying
Whenever you cast your first spell during each opponent's turn, Mischievous Chimera deals 1 damage to each opponent. Scry 1.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Treasure Cruise

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

Lava Storm

Lava Storm deals 2 damage to each attacking creature or Lava Storm deals 2 damage to each blocking creature.

Ponder

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

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Sky Theater Strix

Flying
Whenever you cast a noncreature spell, Sky Theater Strix gets +1/+0 until end of turn.

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.)