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

Chalice of the Void enters the battlefield 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.

Walking Ballista enters the battlefield 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.

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

Mana Bloom enters the battlefield 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.

Creatures you control have base power and toughness X/X until end of turn.

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

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.)

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.) Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

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

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 of your library and the rest on top in any order.)

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.

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

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

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

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.

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

X can't be 0. Target spell's controller exiles it with X delay counters on it. At the beginning of each of that player's upkeeps, if that card is exiled, remove a delay counter from it. If the card has no delay counters on it, the player puts it onto the stack as a copy of the original spell.

Look at the top X cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Flashback—{1}{U}, Exile X blue cards from your graveyard. (You may cast this card from your graveyard for its flashback cost, then exile it. You can't exile Flash of Insight to pay for its own flashback cost.)

Assist (Another player can pay up to {X} of this spell's cost. You choose the value of X.) Destroy target creature with power X or less.

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

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.

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

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

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.

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.

Draw X cards, then discard a card.

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

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

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

Prevent all combat damage X target creatures would deal this turn.

As an additional cost to cast this spell, exile X cards from your graveyard. You draw X cards and you lose X life.

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.

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

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.) Choose target creature, then choose another target creature for each time this spell was kicked. Put X +1/+1 counters on each of them.

Target player draws X cards.

Exile X target cards from target player's graveyard. For each card exiled this way, that player loses 1 life and you gain 1 life.

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.

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}.

Creatures of the creature type of your choice get +X/+X until end of turn.

Cast this spell only during combat on an opponent's turn. Return X target creature cards from your graveyard to the battlefield. Sacrifice those creatures at the beginning of the next end step.

{T}: Add {C}. Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped. {T}: Add {U} or {B}.

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

{1}, {T}: Add {U}{B}.

Dimir Aqueduct enters the battlefield tapped. When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand. {T}: Add {U}{B}.

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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

({T}: Add {G}.)

Golgari Rot Farm enters the battlefield tapped. When Golgari Rot Farm enters the battlefield, return a land you control to its owner's hand. {T}: Add {B}{G}.

({T}: Add {U}.)

Krosan Verge enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Krosan Verge: Search your library for a Forest card and a Plains card, put them onto the battlefield tapped, then shuffle.

If you control two or more other lands, Lair of the Hydra enters the battlefield tapped. {T}: Add {G}. {X}{G}: Until end of turn, Lair of the Hydra becomes an X/X green Hydra creature. It's still a land. X can't be 0.

{T}: Add {C}. {T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Opulent Palace enters the battlefield tapped. {T}: Add {B}, {G}, or {U}.

Simic Growth Chamber enters the battlefield tapped. When Simic Growth Chamber enters the battlefield, return a land you control to its owner's hand. {T}: Add {G}{U}.

({T}: Add {U} or {B}.) Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

Temple of Deceit enters the battlefield tapped. When Temple of Deceit enters the battlefield, scry 1. {T}: Add {U} or {B}.

Temple of Malady enters the battlefield tapped. When Temple of Malady enters the battlefield, scry 1. {T}: Add {B} or {G}.

Temple of Mystery enters the battlefield tapped. When Temple of Mystery enters the battlefield, scry 1. {T}: Add {G} or {U}.

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Thriving Grove enters the battlefield tapped. As Thriving Grove enters the battlefield, choose a color other than green. {T}: Add {G} or one mana of the chosen color.

Thriving Isle enters the battlefield tapped. As Thriving Isle enters the battlefield, choose a color other than blue. {T}: Add {U} or one mana of the chosen color.

Thriving Moor enters the battlefield tapped. As Thriving Moor enters the battlefield, choose a color other than black. {T}: Add {B} or one mana of the chosen color.

Vivid Creek enters the battlefield tapped with two charge counters on it. {T}: Add {U}. {T}, Remove a charge counter from Vivid Creek: Add one mana of any color.

Vivid Grove enters the battlefield tapped with two charge counters on it. {T}: Add {G}. {T}, Remove a charge counter from Vivid Grove: Add one mana of any color.

Vivid Marsh enters the battlefield tapped with two charge counters on it. {T}: Add {B}. {T}, Remove a charge counter from Vivid Marsh: Add one mana of any color.

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.

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

As an additional cost to cast this spell, pay X life. Each other player loses X life.

Spend only black mana on X. Consume Spirit deals X damage to any target and you gain X life.

Return X target nonland permanents to their owners' hands.

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.

Reveal the top X cards of your library. You may put any number of permanent 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 into your graveyard.

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

(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.

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.

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.

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

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."

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.