Spellrune Howler

Whenever you cast an instant or sorcery spell, Spellrune Howler gets +2/+2 until end of turn.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Spellrune Painter

Whenever you cast an instant or sorcery spell, Spellrune Painter gets +1/+1 until end of turn.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Spellrune Painter // Spellrune Howler

Play with Fire

Play with Fire deals 2 damage to any target. If a player is dealt damage this way, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Swiftwater Cliffs

Swiftwater Cliffs enters tapped.
When Swiftwater Cliffs enters, you gain 1 life.
{T}: Add {U} or {R}.

Mountain

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Island

Arcane Infusion

Look at the top four cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Flashback {3}{U}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Big Score

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.")

Electric Revelation

As an additional cost to cast this spell, discard a card.
Draw two cards.
Flashback {3}{R} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

Ashmouth Dragon

Flying
Whenever you cast an instant or sorcery spell, Ashmouth Dragon deals 2 damage to any target.

Smoldering Egg

Defender
Whenever you cast an instant or sorcery spell, put a number of ember counters on Smoldering Egg equal to the amount of mana spent to cast that spell. Then if Smoldering Egg has seven or more ember counters on it, remove them and transform Smoldering Egg.

Smoldering Egg // Ashmouth Dragon

Abrade

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

Cathartic Pyre

Choose one —
• Cathartic Pyre deals 3 damage to target creature or planeswalker.
• Discard up to two cards, then draw that many cards.

Festival Crasher

Whenever you cast an instant or sorcery spell, Festival Crasher gets +2/+0 until end of turn.

Storm Skreelix

Flying
Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, Storm Skreelix gets +2/+0 until end of turn.

Geistflame Reservoir

Whenever you cast an instant or sorcery spell, put a charge counter on Geistflame Reservoir.
{1}{R}, {T}, Remove any number of charge counters from Geistflame Reservoir: It deals that much damage to any target.
{1}{R}, {T}: Exile the top card of your library. You may play that card this turn.

Consider

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

Burn Down the House

Choose one —
• Burn Down the House deals 5 damage to each creature and each planeswalker.
• Create three 1/1 red Devil creature tokens with "When this creature dies, it deals 1 damage to any target." They gain haste until end of turn.

Memory Deluge

Look at the top X cards of your library, where X is the amount of mana spent to cast this spell. Put two of them into your hand and the rest on the bottom of your library in a random order.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Thirst for Discovery

Draw three cards. Then discard two cards unless you discard a basic land card.

Stormcarved Coast

Stormcarved Coast enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Wandering Mind

Flying
When Wandering Mind enters, look at the top six cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Seize the Storm

Create a red Elemental creature token with trample and "This creature's power and toughness are each equal to the number of instant and sorcery cards in your graveyard plus the number of cards with flashback you own in exile."
Flashback {6}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)