Altered Ego

This spell can't be countered.
You may have Altered Ego enter as a copy of any creature on the battlefield, except it enters with X additional +1/+1 counters on it.

Arcane Signet

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

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.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Gargos, Vicious Watcher

Vigilance
Hydra spells you cast cost {4} less to cast.
Whenever a creature you control becomes the target of a spell, Gargos, Vicious Watcher fights up to one target creature you don't control.

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.

Swamp

Nyxbloom Ancient

Trample
If you tap a permanent for mana, it produces three times as much of that mana instead.

Hungering Hydra

Hungering Hydra enters with X +1/+1 counters on it.
Hungering Hydra can't be blocked by more than one creature.
Whenever Hungering Hydra is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Deathrite Shaman

{T}: Exile target land card from a graveyard. Add one mana of any color.
{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.
{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

Elvish Mystic

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.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Zaxara, the Exemplary

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.

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Finale of Devastation

Search your library and/or graveyard for a creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle. If X is 10 or more, creatures you control get +X/+X and gain haste until end of turn.

Exsanguinate

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

Arbor Elf

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Tropical Island

Curse of the Swine

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

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Llanowar Elves

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Gaea's Cradle

{T}: Add {G} for each creature you control.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Command Tower

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Protean Hydra

Protean Hydra enters with X +1/+1 counters on it.
If damage would be dealt to Protean Hydra, prevent that damage and remove that many +1/+1 counters from it.
Whenever a +1/+1 counter is removed from Protean Hydra, put two +1/+1 counters on it at the beginning of the next end step.

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.

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If Incubation Druid has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Veil of Summer

Draw a card if an opponent has cast a blue or black spell this turn. Spells you control can't be countered this turn. You and permanents you control gain hexproof from blue and from black until end of turn. (You and they can't be the targets of blue or black spells or abilities your opponents control.)

Blue Sun's Zenith

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

Unbound Flourishing

Whenever you cast a permanent spell with a mana cost that contains {X}, double the value of X.
Whenever you cast an instant or sorcery spell or activate an ability, if that spell's mana cost or that ability's activation cost contains {X}, copy that spell or ability. You may choose new targets for the copy.

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Exotic Orchard

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

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Helix Pinnacle

Shroud (This enchantment can't be the target of spells or abilities.)
{X}: Put X tower counters on Helix Pinnacle.
At the beginning of your upkeep, if there are 100 or more tower counters on Helix Pinnacle, you win the game.

Counterspell

Simic Ascendancy

{1}{G}{U}: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy.
At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

Asceticism

Creatures you control have hexproof.
{1}{G}: Regenerate target creature. (The next time it would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Sol Ring

Primordial Hydra

Primordial Hydra enters with X +1/+1 counters on it.
At the beginning of your upkeep, double the number of +1/+1 counters on Primordial Hydra.
Primordial Hydra has trample as long as it has ten or more +1/+1 counters on it.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Stroke of Genius

Lifeblood Hydra

Trample
Lifeblood Hydra enters with X +1/+1 counters on it.
When Lifeblood Hydra dies, you gain life and draw cards equal to its power.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Pull from Tomorrow

Torment of Hailfire

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

Craterhoof Behemoth

Haste
When Craterhoof Behemoth enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Windswept Heath

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Forest

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Vedalken Orrery

You may cast spells as though they had flash.

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.

Hooded Hydra

Hooded Hydra enters with X +1/+1 counters on it.
When Hooded Hydra dies, create a 1/1 green Snake creature token for each +1/+1 counter on it.
Morph {3}{G}{G}
As Hooded Hydra is turned face up, put five +1/+1 counters on it.

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.)

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Morphic Pool

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters with X +1/+1 counters on it.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

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}.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Yavimaya Coast

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

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Kalonian Hydra

Trample
Kalonian Hydra enters with four +1/+1 counters on it.
Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Underground Sea

Steelbane Hydra

Steelbane Hydra enters with X +1/+1 counters on it.
{2}{G}, Remove a +1/+1 counter from Steelbane Hydra: Destroy target artifact or enchantment.

Hydroid Krasis

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.

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

Elves of Deep Shadow

{T}: Add {B}. Elves of Deep Shadow deals 1 damage to you.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Birds of Paradise

Bayou

Island

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.