Belbe's Armor

{X}, {T}: Target creature gets -X/+X until end of turn.

Runed Arch

Runed Arch enters tapped.
{X}, {T}, Sacrifice Runed Arch: X target creatures with power 2 or less can't be blocked this turn.

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.

Thought Dissector

{X}, {T}: Target opponent reveals cards from the top of their library until an artifact card or X cards are revealed, whichever comes first. If an artifact card is revealed this way, put it onto the battlefield under your control and sacrifice Thought Dissector. Put the rest of the revealed cards into that player's graveyard.

Astral Cornucopia

Astral Cornucopia enters with X charge counters on it.
{T}: Choose a color. Add one mana of that color for each charge counter on Astral Cornucopia.

Whetwheel

{X}{X}, {T}: Target player mills X cards.
Morph {3} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

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.

Entrancing Lyre

You may choose not to untap Entrancing Lyre during your untap step.
{X}, {T}: Tap target creature with power X or less. It doesn't untap during its controller's untap step for as long as Entrancing Lyre remains tapped.

Clown Car

When Clown Car enters, roll X six-sided dice. For each odd result, create a 1/1 white Clown Robot artifact creature token. For each even result, put a +1/+1 counter on Clown Car.
Crew 2

Hangarback Walker

Hangarback Walker enters with X +1/+1 counters on it.
When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.
{1}, {T}: Put a +1/+1 counter on Hangarback Walker.

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.

Candelabra of Tawnos

Illusionary Mask

{X}: You may choose a creature card in your hand whose mana cost could be paid by some amount of, or all of, the mana you spent on {X}. If you do, you may cast that card face down as a 2/2 creature spell without paying its mana cost. If the creature that spell becomes as it resolves has not been turned face up and would assign or deal damage, be dealt damage, or become tapped, instead it's turned face up and assigns or deals damage, is dealt damage, or becomes tapped. Activate only as a sorcery.

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."

Puffer Extract

{X}, {T}: Target creature you control gets +X/+X until end of turn. Destroy it at the beginning of the next end step.

Emblazoned Golem

Kicker {X} (You may pay an additional {X} as you cast this spell.)
Spend only colored mana on X. No more than one mana of each color may be spent this way.
If Emblazoned Golem was kicked, it enters with X +1/+1 counters on it.

Ent-Draught Basin

{X}, {T}: Put a +1/+1 counter on target creature with power X. Activate only as a sorcery.

The Mycosynth Gardens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{X}, {T}: The Mycosynth Gardens becomes a copy of target nontoken artifact you control with mana value X.

Citanul Flute

{X}, {T}: Search your library for a creature card with mana value X or less, reveal it, put it into your hand, then shuffle.

Reflecting Mirror

{X}, {T}: Change the target of target spell with a single target if that target is you. The new target must be a player. X is twice the mana value of that spell.

Clockwork Swarm

Clockwork Swarm enters with four +1/+0 counters on it.
Clockwork Swarm can't be blocked by Walls.
At end of combat, if Clockwork Swarm attacked or blocked this combat, remove a +1/+0 counter from it.
{X}, {T}: Put up to X +1/+0 counters on Clockwork Swarm. This ability can't cause the total number of +1/+0 counters on Clockwork Swarm to be greater than four. Activate only during your upkeep.

Talon of Pain

Whenever a source you control other than Talon of Pain deals damage to an opponent, put a charge counter on Talon of Pain.
{X}, {T}, Remove X charge counters from Talon of Pain: It deals X damage to any target.

Wizard's Rockets

Wizard's Rockets enters tapped.
{X}, {T}, Sacrifice Wizard's Rockets: Add X mana in any combination of colors.
When Wizard's Rockets is put into a graveyard from the battlefield, draw a card.

The Mana Rig

Whenever you cast a multicolored spell, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")
{X}{X}{X}, {T}: 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.

Mishra's Helix

Ice Cauldron

{X}, {T}: You may exile a nonland card from your hand. You may cast that card for as long as it remains exiled. Put a charge counter on Ice Cauldron and note the type and amount of mana spent to pay this activation cost. Activate only if there are no charge counters on Ice Cauldron.
{T}, Remove a charge counter from Ice Cauldron: Add Ice Cauldron's last noted type and amount of mana. Spend this mana only to cast the last card exiled with Ice Cauldron.

Omarthis, Ghostfire Initiate

Omarthis, Ghostfire Initiate enters with X +1/+1 counters on it.
Whenever you put one or more +1/+1 counters on another colorless creature, you may put a +1/+1 counter on Omarthis.
When Omarthis dies, manifest a number of cards from the top of your library equal to the number of counters on it.

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.

Snake Basket

{X}, Sacrifice Snake Basket: Create X 1/1 green Snake creature tokens. Activate only as a sorcery.

Chimeric Coils

{X}{1}: Chimeric Coils becomes an X/X Construct artifact creature. Sacrifice it at the beginning of the next end step.

Clockwork Steed

Clockwork Steed enters with four +1/+0 counters on it.
Clockwork Steed can't be blocked by artifact creatures.
At end of combat, if Clockwork Steed attacked or blocked this combat, remove a +1/+0 counter from it.
{X}, {T}: Put up to X +1/+0 counters on Clockwork Steed. This ability can't cause the total number of +1/+0 counters on Clockwork Steed to be greater than four. Activate only during your upkeep.

Heroes' Podium

Each legendary creature you control gets +1/+1 for each other legendary creature you control.
{X}, {T}: Look at the top X cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Clockwork Beast

Clockwork Beast enters with seven +1/+0 counters on it.
At end of combat, if Clockwork Beast attacked or blocked this combat, remove a +1/+0 counter from it.
{X}, {T}: Put up to X +1/+0 counters on Clockwork Beast. This ability can't cause the total number of +1/+0 counters on Clockwork Beast to be greater than seven. Activate only during your upkeep.

Voodoo Doll

At the beginning of your upkeep, put a pin counter on Voodoo Doll.
At the beginning of your end step, if Voodoo Doll is untapped, destroy Voodoo Doll and it deals damage to you equal to the number of pin counters on it.
{X}{X}, {T}: Voodoo Doll deals damage equal to the number of pin counters on it to any target. X is the number of pin counters on Voodoo Doll.

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

Aladdin's Lamp

{X}, {T}: The next time you would draw a card this turn, instead look at the top X cards of your library, put all but one of them on the bottom of your library in a random order, then draw a card. X can't be 0.

Steel Hellkite

Flying
{2}: Steel Hellkite gets +1/+0 until end of turn.
{X}: Destroy each nonland permanent with mana value X whose controller was dealt combat damage by Steel Hellkite this turn. Activate only once each turn.

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.

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.

Riptide Replicator

As Riptide Replicator enters, choose a color and a creature type.
Riptide Replicator enters with X charge counters on it.
{4}, {T}: Create an X/X creature token of the chosen color and type, where X is the number of charge counters on Riptide Replicator.

Endless One

Endless One enters with X +1/+1 counters on it.

Chimeric Staff

{X}: Chimeric Staff becomes an X/X Construct artifact creature until end of turn.

Blast Zone

Blast Zone enters with a charge counter on it.
{T}: Add {C}.
{X}{X}, {T}: Put X charge counters on Blast Zone.
{3}, {T}, Sacrifice Blast Zone: Destroy each nonland permanent with mana value equal to the number of charge counters on Blast Zone.

Elementalist's Palette

Whenever you cast a spell with {X} in its mana cost, put two charge counters on Elementalist's Palette.
{T}: Add one mana of any color.
{T}: Add {C} for each charge counter on Elementalist's Palette. Spend this mana only on costs that contain {X}.

Shifting Wall

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

Helm of Obedience

{X}, {T}: Target opponent mills a card, then repeats this process until a creature card or X cards have been put into their graveyard this way, whichever comes first. If one or more creature cards were put into that graveyard this way, sacrifice Helm of Obedience and put one of them onto the battlefield under your control. X can't be 0.

Bargaining Table

{X}, {T}: Draw a card. X is the number of cards in an opponent's hand.

Orochi Hatchery

Orochi Hatchery enters with X charge counters on it.
{5}, {T}: Create a 1/1 green Snake creature token for each charge counter on Orochi Hatchery.

Soul Foundry

Imprint — When Soul Foundry enters, you may exile a creature card from your hand.
{X}, {T}: Create a token that's a copy of the exiled card. X is the mana value of that card.

Prototype Portal

Imprint — When Prototype Portal enters, you may exile an artifact card from your hand.
{X}, {T}: Create a token that's a copy of the exiled card. X is the mana value of that card.

Floodwater Dam

Phyrexian Marauder

Phyrexian Marauder enters with X +1/+1 counters on it.
Phyrexian Marauder can't block.
Phyrexian Marauder can't attack unless you pay {1} for each +1/+1 counter on it.

Sands of Delirium

Clockwork Avian

Flying
Clockwork Avian enters with four +1/+0 counters on it.
At end of combat, if Clockwork Avian attacked or blocked this combat, remove a +1/+0 counter from it.
{X}, {T}: Put up to X +1/+0 counters on Clockwork Avian. This ability can't cause the total number of +1/+0 counters on Clockwork Avian to be greater than four. Activate only during your upkeep.

Well of Lost Dreams

Whenever you gain life, you may pay {X}, where X is less than or equal to the amount of life you gained. If you do, draw X cards.

Ventifact Bottle

{X}{1}, {T}: Put X charge counters on Ventifact Bottle. Activate only as a sorcery.
At the beginning of your first main phase, if Ventifact Bottle has a charge counter on it, tap it and remove all charge counters from it. Add {C} for each charge counter removed this way.

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters with X +1/+1 counters on 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.

Karn's Sylex

Karn's Sylex enters tapped.
Players can't pay life to cast spells or to activate abilities that aren't mana abilities.
{X}, {T}, Exile Karn's Sylex: Destroy each nonland permanent with mana value X or less. Activate only as a sorcery.

Panacea

{X}{X}, {T}: Prevent the next X damage that would be dealt to any target this turn.