Counterspell

Terrasymbiosis

Whenever you put one or more +1/+1 counters on a creature you control, you may draw that many cards. Do this only once each turn.

Bristly Bill, Spine Sower

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature.
{3}{G}{G}: Double the number of +1/+1 counters on each creature you control.

Nature's Rhythm

Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.
Harmonize {X}{G}{G}{G}{G} (You may cast this card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by an amount of generic mana equal to its power. Then exile this spell.)

Repulsive Mutation

Put X +1/+1 counters on target creature you control. Then counter up to one target spell unless its controller pays mana equal to the greatest power among creatures you control.

Tester of the Tangential

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
At the beginning of combat on your turn, you may pay {X}. When you do, move X +1/+1 counters from this creature onto another target creature.

Bred for the Hunt

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, you may draw a card.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Ripples of Potential

Proliferate, then choose any number of permanents you control that had a counter put on them this way. Those permanents phase out. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there. Treat phased-out permanents and anything attached to them as though they don't exist until their controller's next turn.)

Quandrix Command

Choose two —
• Return target creature or planeswalker to its owner's hand.
• Counter target artifact or enchantment spell.
• Put two +1/+1 counters on target creature.
• Target player shuffles up to three target cards from their graveyard into their library.

Berta, Wise Extrapolator

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on Berta, add one mana of any color.
{X}, {T}: Create a 0/0 green and blue Fractal creature token and put X +1/+1 counters on it.

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.

Nesting Grounds

{T}: Add {C}.
{1}, {T}: Move a counter from target permanent you control onto a second target permanent. Activate only as a sorcery.

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Expansion Algorithm

Proliferate X times. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there.)

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

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.

Vineglimmer Snarl

As this land enters, you may reveal a Forest or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {G} or {U}.

Topiary Lecturer

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
{T}: Add an amount of {G} equal to this creature's power.

Alchemist's Refuge

{T}: Add {C}.
{G}{U}, {T}: You may cast spells this turn as though they had flash.

Island

Germination Practicum

Put two +1/+1 counters on each creature you control.
Paradigm (Then exile this spell. After you first resolve a spell with this name, you may cast a copy of it from exile without paying its mana cost at the beginning of each of your first main phases.)

Fathom Mage

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever a +1/+1 counter is put on this creature, you may draw a card.

Branching Evolution

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.

Gyre Sage

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
{T}: Add {G} for each +1/+1 counter on this creature.

Textbook Tabulator

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Lyla, Holographic Assistant

Whenever you draw a card, put a +1/+1 counter on target creature.

Oran-Rief, the Vastwood

This land enters tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered this turn.

Sodden Verdure

({T}: Add {G} or {U}.)
This land enters tapped unless you control two or more basic lands.

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Pollywog Prodigy

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever an opponent casts a noncreature spell with mana value less than this creature's power, draw a card.

Embrace the Paradox

Draw three cards. You may put a land card from your hand onto the battlefield tapped.

Deep Sight

Tam, Observant Sequencer

Landfall — Whenever a land you control enters, Tam becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Tam, Observant Sequencer // Deep Sight

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on this creature.
At the beginning of your upkeep, you may move any number of +1/+1 counters from this creature onto other creatures.

Evolution Witness

{1}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Whenever one or more +1/+1 counters are put on this creature, return target permanent card from your graveyard to your hand.

Arcane Signet

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

Radstorm

Storm (When you cast this spell, copy it for each spell cast before it this turn.)
Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Turbulent Wilderness

({T}: Add {G} or {U}.)
This land enters tapped unless your opponents control eight or more lands.

Llanowar Elves

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Pensive Professor

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on this creature, draw a card.

Fellwar Stone

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

Applied Geometry

Create a token that's a copy of target non-Aura permanent you control, except it's a 0/0 Fractal creature in addition to its other types. Put six +1/+1 counters on it.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Rain-Slicked Copse

({T}: Add {G} or {U}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Botanical Sanctum

This land enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {U}.

Rejuvenating Springs

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

Forest

Willowrush Verge

{T}: Add {U}.
{T}: Add {G}. Activate only if you control a Forest or an Island.

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 this enchantment.
At the beginning of your upkeep, if this enchantment has twenty or more growth counters on it, you win the game.

Body of Research

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is the number of cards in your library.

Fractal Summoning

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it.

Ride the Shoopuf

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature you control.
{5}{G}{G}: This enchantment becomes a 7/7 Beast creature in addition to its other types.

Hinterland Harbor

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

Quandrix Charm

Choose one —
• Counter target spell unless its controller pays {2}.
• Destroy target enchantment.
• Target creature has base power and toughness 5/5 until end of turn.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Birds of Paradise

Hungry Graffalon

Reach
Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)

The Earth Crystal

Green spells you cast cost {1} less to cast.
If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.
{4}{G}{G}, {T}: Distribute two +1/+1 counters among one or two target creatures you control.

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. This artifact deals 1 damage to you.

Sphere Grid

Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.
Unlock Ability — Creatures you control with +1/+1 counters on them have reach and trample.

Freed from the Real

Enchant creature
{U}: Tap enchanted creature.
{U}: Untap enchanted creature.

Ozolith, the Shattered Spire

If one or more +1/+1 counters would be put on an artifact or creature you control, that many plus one +1/+1 counters are put on it instead.
{1}{G}, {T}: Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery.
Cycling {2} ({2}, Discard this card: Draw a card.)

Golden Ratio

Draw a card for each different power among creatures you control.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is this creature's power.

Dreamroot Cascade

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

Fractal Tender

Ward {2}
Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
At the beginning of each end step, if you put a counter on this creature this turn, create a 0/0 green and blue Fractal creature token and put three +1/+1 counters on it.

Breeding Pool

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

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Wave Goodbye

Return each creature without a +1/+1 counter on it to its owner's hand.

Lessons from Life

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If this creature 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.)

Cuboid Colony

Flash
Flying, trample
Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)

Zimone, Paradox Sculptor

At the beginning of combat on your turn, put a +1/+1 counter on each of up to two target creatures you control.
{G}{U}, {T}: Double the number of each kind of counter on up to two target creatures and/or artifacts you control.

Ambitious Augmenter

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
When this creature dies, if it had one or more counters on it, create a 0/0 green and blue Fractal creature token, then put this creature's counters on that token.