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.

Entity Tracker

Flash
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, draw a card.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Command Tower

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

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Mountain

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Warped Space

Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast from exile.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Charred Foyer

At the beginning of your upkeep, exile the top card of your library. You may play it this turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Charred Foyer // Warped Space

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Sunset Strikemaster

{T}: Add {R}.
{2}{R}, {T}, Sacrifice this creature: It deals 6 damage to target creature with flying.

Negate

Counterspell

Arcane Signet

Defaced Gallery

Whenever you attack, attacking creatures you control get +1/+0 until end of turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Painter's Studio

When you unlock this door, exile the top two cards of your library. You may play them until the end of your next turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Painter's Studio // Defaced Gallery

Keranos, God of Storms

Indestructible
As long as your devotion to blue and red is less than seven, Keranos isn't a creature.
Reveal the first card you draw on each of your turns. Whenever you reveal a land card this way, draw a card. Whenever you reveal a nonland card this way, Keranos deals 3 damage to any target.

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.)

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Leyline of Anticipation

If this card is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Etching of Kumano

Haste
If a creature dealt damage this turn by a source you controlled would die, exile it instead.

Kumano Faces Kakkazan

(As this Saga enters and after your draw step, add a lore counter.)
I — This Saga deals 1 damage to each opponent and each planeswalker they control.
II — When you next cast a creature spell this turn, that creature enters with an additional +1/+1 counter on it.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Kumano Faces Kakkazan // Etching of Kumano

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Molten Gatekeeper

Whenever another creature you control enters, this creature deals 1 damage to each opponent.
Unearth {R} ({R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Witty Roastmaster

Alliance — Whenever another creature you control enters, this creature deals 1 damage to each opponent.

Castle Vantress

This land enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Castle Embereth

This land enters tapped unless you control a Mountain.
{T}: Add {R}.
{1}{R}{R}, {T}: Creatures you control get +1/+0 until end of turn.

Firebrand Archer

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

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

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Niv-Mizzet, Parun

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

One with the Multiverse

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library.
Once during each of your turns, you may cast a spell from your hand or the top of your library without paying its mana cost.

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on this creature.
When this creature dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on this creature. (They can't be blocked as long as defending player controls an Island.)

Boltwave

Boltwave deals 3 damage to each opponent.

Silver Myr

Exotic Orchard

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

Island

Desolate Lighthouse

{T}: Add {C}.
{1}{U}{R}, {T}: Draw a card, then discard a card.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Amphibian Downpour

Flash
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies. Copies become tokens.)
Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1.

Iron Myr

Izzet Signet

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice this land: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Mechanized Warfare

If a red or artifact source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Fear of Sleep Paralysis

Flying
Eerie — Whenever this creature or another enchantment you control enters and whenever you fully unlock a Room, tap up to one target creature and put a stun counter on it.
Stun counters can't be removed from permanents your opponents control. (They won't untap if they have stun counters.)

Dragon's Rage Channeler

Whenever you cast a noncreature spell, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
Delirium — As long as there are four or more card types among cards in your graveyard, this creature gets +2/+2, has flying, and attacks each combat if able.

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

Coruscation Mage

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Fellwar Stone

Utter Insignificance

Flash
Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.
{2}{C}: Exile enchanted creature.

Ominous Seas

Whenever you draw a card, put a foreshadow counter on this enchantment.
Remove eight foreshadow counters from this enchantment: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Fiery Emancipation

If a source you control would deal damage to a permanent or player, it deals triple that damage to that permanent or player instead.

Frantic Search

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

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
{T}: Draw a card.

Commander's Sphere

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

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Dress Down

Flash
When this enchantment enters, draw a card.
Creatures lose all abilities.
At the beginning of the end step, sacrifice this enchantment.

Fear of Impostors

Flash
When this creature enters, counter target spell. Its controller manifests dread. (That player looks at the top two cards of their library, then puts one onto the battlefield face down as a 2/2 creature and the other into their graveyard. If it's a creature card, it can be turned face up any time for its mana cost.)

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."

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Kessig Flamebreather

Steaming Sauna

You have no maximum hand size.
At the beginning of your end step, draw a card.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Roaring Furnace

When you unlock this door, this Room deals damage equal to the number of cards in your hand to target creature an opponent controls.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Roaring Furnace // Steaming Sauna

Ovika, Enigma Goliath

Flying
Ward—{3}, Pay 3 life.
Whenever you cast a noncreature spell, create X 1/1 red Phyrexian Goblin creature tokens, where X is the mana value of that spell. They gain haste until end of turn.

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.)

Frostcliff Siege

As this enchantment enters, choose Jeskai or Temur.
• Jeskai — Whenever one or more creatures you control deal combat damage to a player, draw a card.
• Temur — Creatures you control get +1/+0 and have trample and haste.

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Steam Clean

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

Scalding Viper

Whenever an opponent casts a spell with mana value 3 or less, this creature deals 1 damage to that player.

Scalding Viper // Steam Clean

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Powerbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, you may cast that card without paying its mana cost if the two spells have the same mana value.

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.