Squall Line

Squall Line deals X damage to each creature with flying and each player.

Broken Ambitions

Counter target spell unless its controller pays {X}. Clash with an opponent. If you win, that spell's controller mills four cards. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Sylvan Offering

Choose an opponent. You and that player each create an X/X green Treefolk creature token.
Choose an opponent. You and that player each create X 1/1 green Elf Warrior creature tokens.

Dominate

Gain control of target creature with mana value X or less.

Blue Sun's Zenith

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

Muse Vortex

Exile the top X cards of your library. You may cast an instant or sorcery spell with mana value X or less from among them without paying its mana cost. Then put the exiled instant and sorcery cards that weren't cast this way into your hand and the rest on the bottom of your library in a random order.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Ingenious Mastery

You may pay {2}{U} rather than pay this spell's mana cost.
If the {2}{U} cost was paid, you draw three cards, then an opponent creates two Treasure tokens and they scry 2. If that cost wasn't paid, you draw X cards.

Commander's Insight

Target player draws X cards plus an additional card for each time they've cast a commander from the command zone this game.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

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.

Finale of Eternity

Destroy up to three target creatures with toughness X or less. If X is 10 or more, return all creature cards from your graveyard to the battlefield.

Pest Infestation

Destroy up to X target artifacts and/or enchantments. Create twice X 1/1 black and green Pest creature tokens with "When this creature dies, you gain 1 life."

Forced March

Destroy all creatures with mana value X or less.

Gelatinous Genesis

Mind Spring

Stolen by the Fae

Return target creature with mana value X to its owner's hand. You create X 1/1 blue Faerie creature tokens with flying.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Multiple Choice

If X is 1, scry 1, then draw a card.
If X is 2, you may choose a player. They return a creature they control to its owner's hand.
If X is 3, create a 4/4 blue and red Elemental creature token.
If X is 4 or more, do all of the above.

Long Rest

Return X target cards with different mana values from your graveyard to your hand. If eight or more cards were returned to your hand this way, your life total becomes equal to your starting life total. Exile Long Rest.

Damnable Pact

Target player draws X cards and loses X life.

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.)

Silkguard

Put a +1/+1 counter on each of up to X target creatures you control.
Auras, Equipment, and modified creatures you control gain hexproof until end of turn. (Equipment, Auras you control, and counters are modifications.)

Braingeyser

Dread Summons

Each player mills X cards. For each creature card put into a graveyard this way, you create a tapped 2/2 black Zombie creature token. (To mill a card, a player puts the top card of their library into their graveyard.)

Distorting Wake

Return X target nonland permanents to their owners' hands.

Clash of Wills

Counter target spell unless its controller pays {X}.

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}.

Entrancing Melody

Gain control of target creature with mana value X.

March of Swirling Mist

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Up to X target creatures phase out. (While they're phased out, they're treated as though they don't exist. Each one phases in before its controller untaps during their next untap step.)

March of Wretched Sorrow

As an additional cost to cast this spell, you may exile any number of black cards from your hand. This spell costs {2} less to cast for each card exiled this way.
March of Wretched Sorrow deals X damage to target creature or planeswalker and you gain X life.

Spell Burst

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Counter target spell with mana value X.

Pull from Tomorrow

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Silver Scrutiny

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

Molder

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

Gaze of Granite

Destroy each nonland permanent with mana value X or less.

Terisiare's Devastation

You lose X life and create X tapped Powerstone tokens. Then all creatures get -1/-1 until end of turn for each artifact you control. (The tokens are artifacts with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Erebos's Intervention

Choose one —
• Target creature gets -X/-X until end of turn. You gain X life.
• Exile up to twice X target cards from graveyards.

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.

Diviner's Portent

Roll a d20 and add the number of cards in your hand.
1—14 | Draw X cards.
15+ | Scry X, then draw X cards.

Dregs of Sorrow

Destroy X target nonblack creatures. Draw X cards.

Spinning Wheel Kick

Target creature you control deals damage equal to its power to each of X target creatures and/or planeswalkers.

Displacement Wave

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

Awaken the Woods

Create X 1/1 green Forest Dryad land creature tokens. (They're affected by summoning sickness.)

Repeal

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

Battle at the Bridge

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Target creature gets -X/-X until end of turn. You gain X life.

Profane Command

Choose two —
• Target player loses X life.
• Return target creature card with mana value X or less from your graveyard to the battlefield.
• Target creature gets -X/-X until end of turn.
• Up to X target creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)

Finale of Revelation

Draw X cards. If X is 10 or more, instead shuffle your graveyard into your library, draw X cards, untap up to five lands, and you have no maximum hand size for the rest of the game.
Exile Finale of Revelation.

Dark Salvation

Target player creates X 2/2 black Zombie creature tokens, then up to one target creature gets -1/-1 until end of turn for each Zombie that player controls.

Mass Manipulation

Gain control of X target creatures and/or planeswalkers.

Nylea's Intervention

Choose one —
• Search your library for up to X land cards, reveal them, put them into your hand, then shuffle.
• Nylea's Intervention deals twice X damage to each creature with flying.

Logic Knot

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Counter target spell unless its controller pays {X}.

Drown in Dreams

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Target player draws X cards.
• Target player mills twice X cards.

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Villainous Wealth

Target opponent exiles the top X cards of their library. You may cast any number of spells with mana value X or less from among them without paying their mana costs.