Return from your graveyard to the battlefield any number of target creature cards that each have a different mana value X or less.

As Agadeem, the Undercrypt enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.

{T}: Add {B}.

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.

{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.)

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.

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

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

Target player draws X cards. Shuffle Blue 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.

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.)

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.

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}.

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.

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

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.)

Spend only black mana on X.

Consume Spirit deals X damage to any target and you gain X life.

{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}.

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.

Return X target nonland permanents to their owners' hands.

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.

Sunburst (This enters the battlefield 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.

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.

{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.

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.

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.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

Enchant creature

{U}: Tap enchanted creature.

{U}: Untap enchanted creature.

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.

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.

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}.

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

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

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}.

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.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

(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.

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.

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Counter target spell unless its controller pays {X}.

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.

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

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.

+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.

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.

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.

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."

Opulent Palace enters the battlefield tapped.

{T}: Add {B}, {G}, or {U}.

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."

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.

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}.

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.

({T}: Add {U} or {B}.)

Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

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.

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.

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}.

When The Meathook Massacre enters the battlefield, each creature gets -X/-X until end of turn.

Whenever a creature you control dies, each opponent loses 1 life.

Whenever a creature an opponent controls dies, you gain 1 life.

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.

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

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.

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.

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.

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

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

Return X target cards from your graveyard to your hand. Exile Wildest Dreams.

Reach

Wren's Run Hydra enters the battlefield with X +1/+1 counters on it.

Reinforce X--{X}{G}{G} ({X}{G}{G}, Discard this card: Put X +1/+1 counters on target creature.)

{T}: Add {C}.

{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Deathtouch

{T}: Add two mana of any one color.

Whenever you cast a spell with {X} in its mana cost, create a 0/0 green Hydra creature token, then put X +1/+1 counters on it.