Occult Epiphany

Draw X cards, then discard X cards. Create a 1/1 white Spirit creature token with flying for each card type among cards discarded this way.

Verazol, the Split Current

Verazol, the Split Current enters with a +1/+1 counter on it for each mana spent to cast it.
Whenever you cast a kicked spell, you may remove two +1/+1 counters from Verazol. If you do, copy that spell. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Disintegrate

Disintegrate deals X damage to any target. If it's a creature, it can't be regenerated this turn, and if it would die this turn, exile it instead.

The Crowd Goes Wild

Assist (Another player can pay up to {X} of this spell's cost. You choose the value of X.)
Support X. (Put a +1/+1 counter on each of up to X target creatures.)
Each creature with a +1/+1 counter on it gains trample until end of turn.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Spell Blast

Counter target spell with mana value X. (For example, if that spell's mana cost is {3}{U}{U}, X is 5.)

Epic Experiment

Exile the top X cards of your library. You may cast instant and sorcery spells with mana value X or less from among them without paying their mana costs. Then put all cards exiled this way that weren't cast into your graveyard.

Molder

Destroy target artifact or enchantment with mana value X. It can't be regenerated. You gain X life.

Sigil of Distinction

Sigil of Distinction enters with X charge counters on it.
Equipped creature gets +1/+1 for each charge counter on Sigil of Distinction.
Equip—Remove a charge counter from Sigil of Distinction.

Engineered Explosives

Sunburst (This enters with a charge counter on it for each color of mana spent to cast it.)
{2}, Sacrifice Engineered Explosives: Destroy each nonland permanent with mana value equal to the number of charge counters on Engineered Explosives.

Skyrider Elf

Flying
Converge — Skyrider Elf enters with a +1/+1 counter on it for each color of mana spent to cast it.

Savageborn Hydra

Double strike
Savageborn Hydra enters with X +1/+1 counters on it.
{1}{R/G}: Put a +1/+1 counter on Savageborn Hydra. Activate only as a sorcery.

Lunar Frenzy

Target creature you control gets +X/+0 and gains first strike and trample until end of turn.

Termagant Swarm

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Death Frenzy — When Termagant Swarm dies, create a number of 1/1 green Tyranid creature tokens equal to Termagant Swarm's power.

Reshape

As an additional cost to cast this spell, sacrifice an artifact.
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Demonfire

Demonfire deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead.
Hellbent — If you have no cards in hand, this spell can't be countered and the damage can't be prevented.

Enrage

Target creature gets +X/+0 until end of turn.

New Frontiers

Each player may search their library for up to X basic land cards and put them onto the battlefield tapped. Then each player who searched their library this way shuffles.

Light Up the Night

Light Up the Night deals X damage to any target. It deals X plus 1 damage instead if that target is a creature or planeswalker.
Flashback—{3}{R}, Remove X loyalty counters from among planeswalkers you control. If you cast this spell this way, X can't be 0. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Part Water

X target creatures gain islandwalk until end of turn. (They can't be blocked as long as defending player controls an Island.)

Repeal

Return target nonland permanent with mana value X to its owner's hand.
Draw a card.

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Cryptic Trilobite

Cryptic Trilobite enters with X +1/+1 counters on it.
Remove a +1/+1 counter from Cryptic Trilobite: Add {C}{C}. Spend this mana only to activate abilities.
{1}, {T}: Put a +1/+1 counter on Cryptic Trilobite.

Commune with Lava

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

Detonate

Destroy target artifact with mana value X. It can't be regenerated. Detonate deals X damage to that artifact's controller.

Red Sun's Zenith

Red Sun's Zenith deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead. Shuffle Red Sun's Zenith into its owner's library.

Heat Ray

Heat Ray deals X damage to target creature.

Reap the Past

Return X cards at random from your graveyard to your hand. Exile Reap the Past.

Clash of Wills

Counter target spell unless its controller pays {X}.

Rolling Thunder

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

Thassa's Intervention

Choose one —
• Look at the top X cards of your library. Put up to two of them into your hand and the rest on the bottom of your library in a random order.
• Counter target spell unless its controller pays twice {X}.

Luxurious Libation

Target creature gets +X/+X until end of turn. Create a 1/1 green and white Citizen creature token.

Devil's Play

Devil's Play deals X damage to any target.
Flashback {X}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Winter's Chill

Cast this spell only during combat before blockers are declared.
X can't be greater than the number of snow lands you control.
Choose X target attacking creatures. For each of those creatures, its controller may pay {1} or {2}. If that player doesn't, destroy that creature at end of combat. If that player pays only {1}, prevent all combat damage that would be dealt to and dealt by that creature this combat.

Kaervek's Torch

As long as Kaervek's Torch is on the stack, spells that target it cost {2} more to cast.
Kaervek's Torch deals X damage to any target.

Ravener

Flash
Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
When Ravener enters, target creature attacks target opponent this turn if able.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Chimeric Mass

Chimeric Mass enters with X charge counters on it.
{1}: Until end of turn, Chimeric Mass becomes a Construct artifact creature with "This creature's power and toughness are each equal to the number of charge counters on it."

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Rolling Earthquake

Rolling Earthquake deals X damage to each creature without horsemanship and each player.

Displacement Wave

Return all nonland permanents with mana value X or less to their owners' hands.

Even the Score

This spell costs {U}{U}{U} less to cast if an opponent has drawn four or more cards this turn.
Draw X cards.

Shifting Wall

Defender (This creature can't attack.)
Shifting Wall enters with X +1/+1 counters on it.

Reality Spasm

Choose one —
• Tap X target permanents.
• Untap X target permanents.

Distorting Wake

Return X target nonland permanents to their owners' hands.

Capricopian

Capricopian enters with X +1/+1 counters on it.
{2}: Put a +1/+1 counter on Capricopian, then you may reselect which player Capricopian is attacking. Only the player Capricopian is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

Borrowing the East Wind

Borrowing the East Wind deals X damage to each creature with horsemanship and each player.

Read the Runes

Draw X cards. For each card drawn this way, discard a card unless you sacrifice a permanent.

Increasing Confusion

Target player mills X cards. If this spell was cast from a graveyard, that player mills twice that many cards instead.
Flashback {X}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Krakilin

Krakilin enters with X +1/+1 counters on it.
{1}{G}: Regenerate Krakilin.

Animist's Awakening

Reveal the top X cards of your library. Put all land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, untap those lands.

Aether Tide

As an additional cost to cast this spell, discard X creature cards.
Return X target creatures to their owners' hands.

Wave of Indifference

X target creatures can't block this turn.

Culmination of Studies

Exile the top X cards of your library. For each land card exiled this way, create a Treasure token. For each blue card exiled this way, draw a card. For each red card exiled this way, Culmination of Studies deals 1 damage to each opponent.

Burn from Within

Burn from Within deals X damage to any target. If a creature is dealt damage this way, it loses indestructible until end of turn. If that creature would die this turn, exile it instead.

Condescend

Counter target spell unless its controller pays {X}. 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.)

Tropical Storm

Tropical Storm deals X damage to each creature with flying and 1 additional damage to each blue creature.

Recall

Discard X cards, then return a card from your graveyard to your hand for each card discarded this way. Exile Recall.

Mana Bloom

Mana Bloom enters with X charge counters on it.
Remove a charge counter from Mana Bloom: Add one mana of any color. Activate only once each turn.
At the beginning of your upkeep, if Mana Bloom has no charge counters on it, return it to its owner's hand.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters with X +1/+1 counters on it.

Illuminate

Kicker {2}{R} and/or {3}{U} (You may pay an additional {2}{R} and/or {3}{U} as you cast this spell.)
Illuminate deals X damage to target creature. If this spell was kicked with its {2}{R} kicker, it deals X damage to that creature's controller. If this spell was kicked with its {3}{U} kicker, you draw X cards.

Jaya's Immolating Inferno

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Jaya's Immolating Inferno deals X damage to each of up to three targets.

Silver Scrutiny

You may cast Silver Scrutiny as though it had flash if X is 3 or less.
Draw X cards.

Contortionist Troupe

Contortionist Troupe enters with X +1/+1 counters on it.
Coven — At the beginning of your end step, if you control three or more creatures with different powers, put a +1/+1 counter on target creature you control.

Hour of Eternity

Exile X target creature cards from your graveyard. For each card exiled this way, create a token that's a copy of that card, except it's a 4/4 black Zombie.

Uncage the Menagerie

Search your library for up to X creature cards with different names that each have mana value X, reveal them, put them into your hand, then shuffle.

Nourishing Shoal

You may exile a green card with mana value X from your hand rather than pay this spell's mana cost.
You gain X life.

Feral Hydra

Feral Hydra enters with X +1/+1 counters on it.
{3}: Put a +1/+1 counter on Feral Hydra. Any player may activate this ability.

Volcanic Eruption

Destroy X target Mountains. Volcanic Eruption deals damage to each creature and each player equal to the number of Mountains put into a graveyard this way.

Ugin's Conjurant

Ugin's Conjurant enters with X +1/+1 counters on it.
If damage would be dealt to Ugin's Conjurant while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from Ugin's Conjurant.

Chalice of the Void

Chalice of the Void enters with X charge counters on it.
Whenever a player casts a spell with mana value equal to the number of charge counters on Chalice of the Void, counter that spell.

Choking Vines

Cast this spell only during the declare blockers step.
X target attacking creatures become blocked. Choking Vines deals 1 damage to each of those creatures. (This spell works on creatures that can't be blocked.)

Magmaquake

Magmaquake deals X damage to each creature without flying and each planeswalker.

Iceberg

Iceberg enters with X ice counters on it.
{3}: Put an ice counter on Iceberg.
Remove an ice counter from Iceberg: Add {C}.

Finale of Promise

You may cast up to one target instant card and/or up to one target sorcery card from your graveyard each with mana value X or less without paying their mana costs. If a spell cast this way would be put into your graveyard, exile it instead. If X is 10 or more, copy each of those spells twice. You may choose new targets for the copies.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Kamahl's Druidic Vow

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Look at the top X cards of your library. You may put any number of land and/or legendary permanent cards with mana value X or less from among them onto the battlefield. Put the rest into your graveyard.

Volcanic Geyser

Volcanic Geyser deals X damage to any target.

Blaze

Nahiri's Lithoforming

Sacrifice X lands. For each land sacrificed this way, draw a card. You may play X additional lands this turn. Lands you control enter tapped this turn.

Street Spasm

Street Spasm deals X damage to target creature without flying you don't control.
Overload {X}{X}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Magus Lucea Kane

Spiritual Leader — At the beginning of combat on your turn, put a +1/+1 counter on target creature.
Psychic Stimulus — {T}: Add {C}{C}. When you next cast a spell with {X} in its mana cost or activate an ability with {X} in its activation cost this turn, copy that spell or ability. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Epiphany at the Drownyard

Reveal the top X plus one cards of your library and separate them into two piles. An opponent chooses one of those piles. Put that pile into your hand and the other into your graveyard.

Protean Hydra

Protean Hydra enters with X +1/+1 counters on it.
If damage would be dealt to Protean Hydra, prevent that damage and remove that many +1/+1 counters from it.
Whenever a +1/+1 counter is removed from Protean Hydra, put two +1/+1 counters on it at the beginning of the next end step.

Vastwood Hydra

Vastwood Hydra enters with X +1/+1 counters on it.
When Vastwood Hydra dies, you may distribute a number of +1/+1 counters equal to the number of +1/+1 counters on Vastwood Hydra among any number of creatures you control.

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Balduvian Rage

Target attacking creature gets +X/+0 until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Hurricane

Hurricane deals X damage to each creature with flying and each player.

Flaming Gambit

Flaming Gambit deals X damage to target player or planeswalker. That player or that planeswalker's controller may choose a creature they control and have Flaming Gambit deal that damage to it instead.
Flashback {X}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Briber's Purse

Briber's Purse enters with X gem counters on it.
{1}, {T}, Remove a gem counter from Briber's Purse: Target creature can't attack or block this turn.

Tectonic Break

Crater's Claws

Crater's Claws deals X damage to any target.
Ferocious — Crater's Claws deals X plus 2 damage instead if you control a creature with power 4 or greater.

Ochre Jelly

Trample
Ochre Jelly enters with X +1/+1 counters on it.
Split — When Ochre Jelly dies, if it had two or more +1/+1 counters on it, create a token that's a copy of it at the beginning of the next end step. The token enters with half that many +1/+1 counters on it, rounded down.

Stream of Life

Universal Surveillance

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Draw X cards.

Ghitu Fire

You may cast Ghitu Fire as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
Ghitu Fire deals X damage to any target.

Nissa, Steward of Elements

+2: Scry 2.
0: Look at the top card of your library. If it's a land card or a creature card with mana value less than or equal to the number of loyalty counters on Nissa, Steward of Elements, you may put that card onto the battlefield.
−6: Untap up to two target lands you control. They become 5/5 Elemental creatures with flying and haste until end of turn. They're still lands.

Enshrined Memories

Reveal the top X cards of your library. Put all creature cards revealed this way into your hand and the rest on the bottom of your library in any order.

Venarian Glimmer

Target player reveals their hand. You choose a nonland card with mana value X or less from it. That player discards that card.

Tempt with Vengeance

Tempting offer — Create X 1/1 red Elemental creature tokens with haste. Each opponent may create X 1/1 red Elemental creature tokens with haste. For each opponent who does, create X 1/1 red Elemental creature tokens with haste.

Sweep the Skies

Converge — Create a 1/1 colorless Thopter artifact creature token with flying for each color of mana spent to cast this spell.

Balduvian Hydra

Balduvian Hydra enters with X +1/+0 counters on it.
Remove a +1/+0 counter from Balduvian Hydra: Prevent the next 1 damage that would be dealt to Balduvian Hydra this turn.
{R}{R}{R}: Put a +1/+0 counter on Balduvian Hydra. Activate only during your upkeep.