Heaven deals X damage to each creature with flying.

Hell to Pay deals X damage to target creature. Create a number of tapped Treasure tokens equal to the amount of excess damage dealt to that creature this way.

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)

Endless Swarm — Whenever a land you control enters, you may pay . If you do, return Hormagaunt Horde from your graveyard to your hand.

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.

Trample

When Hugs, Grisly Guardian enters, exile the top X cards of your library. Until the end of your next turn, you may play those cards.

You may play an additional land on each of your turns.

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

When you cast this spell, you gain half X life and draw half X cards. Round down each time.

Flying, trample

Hydroid Krasis enters with X +1/+1 counters on it.

Tap X target creatures.

Ferocious — If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

Kicker and/or (You may pay an additional and/or as you cast this spell.)

Illuminate deals X damage to target creature. If this spell was kicked with its kicker, it deals X damage to that creature's controller. If this spell was kicked with its kicker, you draw X cards.

Assemble X Contraptions. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

Destroy X target artifacts and/or creatures. For each permanent destroyed this way, its controller reveals cards from the top of their library until an artifact or creature card is revealed and exiles that card. Those players put the exiled cards onto the battlefield, then shuffle.

Skulk (This creature can't be blocked by creatures with greater power.)

Ingenious Prodigy enters with X +1/+1 counters on it.

At the beginning of your upkeep, if Ingenious Prodigy has one or more +1/+1 counters on it, you may remove a +1/+1 counter from it. If you do, draw a card.

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)

When Invasion of New Phyrexia enters, create X 2/2 white and blue Knight creature tokens with vigilance.

Ivy Elemental enters with X +1/+1 counters on it.

When Jadelight Spelunker enters, it explores X times. (To have it explore, reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

(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.

As long as Kaervek's Torch is on the stack, spells that target it cost more to cast.

Kaervek's Torch deals X damage to any target.

Look at the top seven cards of your library. Put up to X artifact and/or creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

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

Knickknack Ouphe enters with X +1/+1 counters on it.

When Knickknack Ouphe enters, reveal the top X cards of your library. You may put any number of Aura cards with mana value X or less from among them onto the battlefield. Then put all cards revealed this way that weren't put onto the battlefield on the bottom of your library in a random order.

Krakilin enters with X +1/+1 counters on it.

: Regenerate Krakilin.

Lava Burst deals X damage to any target. If Lava Burst would deal damage to a creature, that damage can't be prevented or dealt instead to another permanent or player.

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Let the Galaxy Burn deals X plus 2 damage to each creature that didn't enter this turn.

Put X +1/+1 counters on target artifact you control. If it isn't a creature or Vehicle, it becomes a 0/0 Construct artifact creature.

Trample, haste

Lightning Serpent enters with X +1/+0 counters on it.

At the beginning of the end step, sacrifice Lightning Serpent.

Delve (Each card you exile from your graveyard while casting this spell pays for .)

Counter target spell unless its controller pays .

Flash

When Lost in the Maze enters, tap X target creatures. Put a stun counter on each of those creatures you don't control. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Tapped creatures you control have hexproof.

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

Maga, Traitor to Mortals enters with X +1/+1 counters on it.

When Maga enters, target player loses life equal to the number of +1/+1 counters on it.

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

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.

As an additional cost to cast this spell, you may exile any number of white cards from your hand. This spell costs less to cast for each card exiled this way.

Exile target artifact, creature, or enchantment with mana value X or less.

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs 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.)

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature's color.)

Create X 1/1 white Soldier creature tokens with lifelink.

Create X 1/1 white Soldier creature tokens. If X is 5 or more, destroy all other creatures.

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)

Terror from the Deep — When Mawloc enters, it fights up to one target creature an opponent controls. If that creature would die this turn, exile it instead.

Destroy each artifact with mana value X or less.

Meteor Shower deals X plus 1 damage divided as you choose among any number of targets.

Exile X target creature cards from your graveyard. For each creature card exiled this way, create a 2/2 black Zombie creature token.

Each opponent reveals cards from the top of their library until they reveal X land cards, then puts all cards revealed this way into their graveyard. X can't be 0.

Draw X cards.

Look at target player's hand and choose X cards from it. That player discards those cards.

Choose two —

• Choose target player. They may discard up to X cards. Then they draw a card for each card discarded this way.

• This spell deals X damage to target creature.

• This spell deals X damage to target planeswalker.

• Target creature gets +X/+0 and gains haste until end of turn.

Flying

You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying.

Kicker (You may pay an additional as you cast this spell.)

If this spell was kicked, it has split second. (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)

Molten Disaster deals X damage to each creature without flying and each player.

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.

As Neverwinter Hydra enters, roll X d6. It enters with a number of +1/+1 counters on it equal to the total of those results.

Trample

Ward (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays .)

When Niko Aris enters, create X Shard tokens. (They're enchantments with ", Sacrifice this enchantment: Scry 1, then draw a card.")

+1: Up to one target creature you control can't be blocked this turn. Whenever that creature deals damage this turn, return it to its owner's hand.

−1: Niko Aris deals 2 damage to target tapped creature for each card you've drawn this turn.

−1: Create a Shard token.

+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.

Each creature gets twice -X/-X until end of turn. Each player gets X rad counters.