Goldvein Hydra

Vigilance, trample, haste
Goldvein Hydra enters with X +1/+1 counters on it.
When Goldvein Hydra dies, create a number of tapped Treasure tokens equal to its power.

Gluttonous Hellkite

When you cast this spell, each player sacrifices X creatures. Gluttonous Hellkite enters with two +1/+1 counters on it for each creature sacrificed this way.
Flying, trample

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

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.

Haunted Ridge

Haunted Ridge enters tapped unless you control two or more other lands.
{T}: Add {B} or {R}.

Sol Ring

Ethereal Haze

Prevent all damage that would be dealt by creatures this turn.

Orzhov Signet

Winds of Abandon

Exile target creature you don't control. For each creature exiled this way, its controller searches their library for a basic land card. Those players put those cards onto the battlefield tapped, then shuffle.
Overload {4}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Darkness

Prevent all combat damage that would be dealt this turn.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Stonecoil Serpent

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

Voracious Hydra

Trample
Voracious Hydra enters with X +1/+1 counters on it.
When Voracious Hydra enters, choose one —
• Double the number of +1/+1 counters on Voracious Hydra.
• Voracious Hydra fights target creature you don't control.

Counterspell

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Magus Lucea Kane

Spiritual Leader — At the beginning of combat on your turn, put a +1/+1 counter on target creature.
Psychic Stimulus — {T}: Add {C}{C}. When you next cast a spell with {X} in its mana cost or activate an ability with {X} in its activation cost this turn, copy that spell or ability. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

The Goose Mother

Flying
The Goose Mother enters with X +1/+1 counters on it.
When The Goose Mother enters, create half X Food tokens, rounded up.
Whenever The Goose Mother attacks, you may sacrifice a Food. If you do, draw a card.

Viridescent Bog

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mistcutter Hydra

This spell can't be countered.
Haste, protection from blue
Mistcutter Hydra enters with X +1/+1 counters on it.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Morphic Pool

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

Luxury Suite

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Izzet Signet

Zoanthrope

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Flying, ward {2}
Warp Blast — When Zoanthrope enters, it deals X damage to any target.

Unexpected Windfall

Skycloud Expanse

Wren's Run Hydra

Reach
Wren's Run Hydra enters 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.)

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.

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Sunscorched Divide

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Golgari Signet

Ferrous Lake

Mana Reflection

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

Kenrith, the Returned King

{R}: All creatures gain trample and haste until end of turn.
{1}{G}: Put a +1/+1 counter on target creature.
{2}{W}: Target player gains 5 life.
{3}{U}: Target player draws a card.
{4}{B}: Put target creature card from a graveyard onto the battlefield under its owner's control.

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.)

Rhystic Study

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

Simic Signet

Shipwreck Marsh

Shipwreck Marsh enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Dreamroot Cascade

Dreamroot Cascade enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Rakdos Signet

Rejuvenating Springs

Rejuvenating Springs enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Arcane Signet

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

Shattered Sanctum

Shattered Sanctum enters tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Azorius Signet

Sundown Pass

Sundown Pass enters tapped unless you control two or more other lands.
{T}: Add {R} or {W}.

Selesnya Signet

Undergrowth Stadium

Undergrowth Stadium enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Bountiful Promenade

Bountiful Promenade enters tapped unless you have two or more opponents.
{T}: Add {G} or {W}.

Nyxborn Hydra

Bestow {X}{G}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Reach, trample
Nyxborn Hydra enters with X +1/+1 counters on it.
Enchanted creature gets +1/+1 for each +1/+1 counter on Nyxborn Hydra and has reach and trample.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Rockfall Vale

Rockfall Vale enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Shivan Devastator

Flying, haste
Shivan Devastator enters with X +1/+1 counters on it.

Desolate Mire

Pirate's Pillage

Negate

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Vault of Champions

Vault of Champions enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Composite Golem

Sacrifice Composite Golem: Add {W}{U}{B}{R}{G}.

Biomancer's Familiar

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it.

Command Tower

Doppelgang

For each of X target permanents, create X tokens that are copies of that permanent.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Boros Signet

Darkwater Catacombs

Exotic Orchard

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

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Dimir Signet

Deathcap Glade

Deathcap Glade enters tapped unless you control two or more other lands.
{T}: Add {B} or {G}.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Overgrown Farmland

Overgrown Farmland enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Collective Resistance

Escalate {G} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Destroy target artifact.
• Destroy target enchantment.
• Target creature gains hexproof and indestructible until end of turn.

Sungrass Prairie

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Gelatinous Genesis

Stormcarved Coast

Stormcarved Coast enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Tibalt's Trickery

Counter target spell. Choose 1, 2, or 3 at random. Its controller mills that many cards, then exiles cards from the top of their library until they exile a nonland card with a different name than that spell. They may cast that card without paying its mana cost. Then they put the exiled cards on the bottom of their library in a random order.

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.")

Termagant Swarm

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Death Frenzy — When Termagant Swarm dies, create a number of 1/1 green Tyranid creature tokens equal to Termagant Swarm's power.

Overflowing Basin

Mossfire Valley

Fierce Guardianship

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

Pull from Tomorrow

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Shadowblood Ridge

Spectator Seating

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Gruul Signet

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.

Tervigon

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Trample
Spawn Termagants — Whenever Tervigon deals combat damage to a player, create that many 1/1 green Tyranid creature tokens.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Zirda, the Dawnwaker

Companion — Each permanent card in your starting deck has an activated ability. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Abilities you activate that aren't mana abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{1}, {T}: Target creature can't block this turn.

The World Tree

The World Tree enters tapped.
{T}: Add {G}.
As long as you control six or more lands, lands you control have "{T}: Add one mana of any color."
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice The World Tree: Search your library for any number of God cards, put them onto the battlefield, then shuffle.