Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Peek

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

Gut Shot

({R/P} can be paid with either {R} or 2 life.)
Gut Shot deals 1 damage to any target.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Spirebluff Canal

Spirebluff Canal enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

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.)

Pyretic Ritual

Mutagenic Growth

({G/P} can be paid with either {G} or 2 life.)
Target creature gets +2/+2 until end of turn.

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Spell Pierce

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

Consider

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

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.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Bedlam Reveler

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Prowess
When Bedlam Reveler enters, discard your hand, then draw three cards.

Mountain

Negate

Serum Visions

Lavaglide Pathway

Riverglide Pathway

Riverglide Pathway // Lavaglide Pathway

Surgical Extraction

({B/P} can be paid with either {B} or 2 life.)
Choose target card in a graveyard other than a basic land card. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles.

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

Twinferno

Choose one —
• When you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Day's Undoing

Each player shuffles their hand and graveyard into their library, then draws seven cards. If it's your turn, end the turn. (Exile all spells and abilities from the stack, including this card. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Island

Hex Parasite

{X}{B/P}: Remove up to X counters from target permanent. For each counter removed this way, Hex Parasite gets +1/+0 until end of turn. ({B/P} can be paid with either {B} or 2 life.)

Kiln Fiend

Whenever you cast an instant or sorcery spell, Kiln Fiend gets +3/+0 until end of turn.

Enigma Drake

Flying
Enigma Drake's power is equal to the number of instant and sorcery cards in your graveyard.

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Marrow Shards

({W/P} can be paid with either {W} or 2 life.)
Marrow Shards deals 1 damage to each attacking creature.

Awoken Horror

When this creature transforms into Awoken Horror, return all non-Horror creatures to their owners' hands.

Thing in the Ice

Defender
Thing in the Ice enters 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.

Thing in the Ice // Awoken Horror

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.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four 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.

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.

Fiery Impulse

Fiery Impulse deals 2 damage to target creature.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Fiery Impulse deals 3 damage instead.

Disrupting Shoal

You may exile a blue card with mana value X from your hand rather than pay this spell's mana cost.
Counter target spell if its mana value is X.