Experiment One

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.)
Remove two +1/+1 counters from Experiment One: Regenerate Experiment One. (The next time this creature would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Cabal Paladin

Whenever you cast a historic spell, Cabal Paladin deals 2 damage to each opponent. (Artifacts, legendaries, and Sagas are historic.)

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Death's Presence

Whenever a creature you control dies, put X +1/+1 counters on target creature you control, where X is the power of the creature that died.

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

Nine-Fingers Keene

Menace
Ward—Pay 9 life.
Whenever Nine-Fingers Keene deals combat damage to a player, look at the top nine cards of your library. You may put a Gate card from among them onto the battlefield. Then if you control nine or more Gates, put the rest into your hand. Otherwise, put the rest on the bottom of your library in a random order.

Forgotten Ancient

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

Cultural Exchange

Choose any number of creatures target player controls. Choose the same number of creatures another target player controls. Those players exchange control of those creatures. (This effect lasts indefinitely.)

Roving Keep

Defender
{7}: Roving Keep gets +2/+0 and gains trample until end of turn. It can attack this turn as though it didn't have defender.

Cemetery Gate

Defender (This creature can't attack.)
Protection from black

Pemmin's Aura

Enchant creature
{U}: Untap enchanted creature.
{U}: Enchanted creature gains flying until end of turn.
{U}: Enchanted creature gains shroud until end of turn. (It can't be the target of spells or abilities.)
{1}: Enchanted creature gets +1/-1 or -1/+1 until end of turn.

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Cyclical Evolution

Target creature gets +3/+3 until end of turn. Exile Cyclical Evolution with three time counters on it.
Suspend 3—{2}{G} (Rather than cast this card from your hand, you may pay {2}{G} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Gemstone Array

{2}: Put a charge counter on Gemstone Array.
Remove a charge counter from Gemstone Array: Add one mana of any color.

Weathered Sentinels

Defender, vigilance, reach, trample
Weathered Sentinels can attack players who attacked you during their last turn as though it didn't have defender.
Whenever Weathered Sentinels attacks, it gets +3/+3 and gains indestructible until end of turn.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Archetype of Endurance

Creatures you control have hexproof.
Creatures your opponents control lose hexproof and can't have or gain hexproof.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Tamiyo, the Moon Sage

+1: Tap target permanent. It doesn't untap during its controller's next untap step.
−2: Draw a card for each tapped creature target player controls.
−8: You get an emblem with "You have no maximum hand size" and "Whenever a card is put into your graveyard from anywhere, you may return it to your hand."

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Court of Garenbrig

When Court of Garenbrig enters, you become the monarch.
At the beginning of your upkeep, distribute two +1/+1 counters among up to two target creatures. Then if you're the monarch, double the number of +1/+1 counters on each creature you control.

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.

Evolutionary Escalation

At the beginning of your upkeep, put three +1/+1 counters on target creature you control and three +1/+1 counters on target creature an opponent controls.

Curse of the Cabal

Target player sacrifices half the permanents they control, rounded down.
Suspend 2—{2}{B}{B} (Rather than cast this card from your hand, you may pay {2}{B}{B} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
At the beginning of each player's upkeep, if Curse of the Cabal is suspended, that player may sacrifice a permanent. If the player does, put two time counters on Curse of the Cabal.

Sanctum Weaver

{T}: Add X mana of any one color, where X is the number of enchantments you control.

Wall of Tombstones

Defender (This creature can't attack.)
At the beginning of your upkeep, change Wall of Tombstones's base toughness to 1 plus the number of creature cards in your graveyard. (This effect lasts indefinitely.)

Case of the Trampled Garden

When this Case enters, distribute two +1/+1 counters among one or two target creatures you control.
To solve — Creatures you control have total power 8 or greater. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you attack, put a +1/+1 counter on target attacking creature. It gains trample until end of turn.

Wall of Air

Defender, flying (This creature can't attack, and it can block creatures with flying.)

Donate

Target player gains control of target permanent you control.

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.)

Fungal Behemoth

Fungal Behemoth's power and toughness are each equal to the number of +1/+1 counters on creatures you control.
Suspend X—{X}{G}{G}. X can't be 0. (Rather than cast this card from your hand, you may pay {X}{G}{G} and exile it with X time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever a time counter is removed from Fungal Behemoth while it's exiled, you may put a +1/+1 counter on target creature.

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Graaz, Unstoppable Juggernaut

Juggernauts you control attack each combat if able.
Juggernauts you control can't be blocked by Walls.
Other creatures you control have base power and toughness 5/3 and are Juggernauts in addition to their other creature types.

Gavel of the Righteous

At the beginning of combat on your turn, put a charge counter on Gavel of the Righteous.
Equipped creature gets +1/+1 for each counter on Gavel of the Righteous.
As long as Gavel of the Righteous has four or more counters on it, equipped creature has double strike.
Equip—Pay {3} or remove a counter from Gavel of the Righteous.

Crossroads Candleguide

When Crossroads Candleguide enters, exile up to one target card from a graveyard.
{2}: Add one mana of any color.

Bandit's Talent

(Gain the next level as a sorcery to add its ability.)
When Bandit's Talent enters, each opponent discards two cards unless they discard a nonland card.
{B}: Level 2
At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 2 life.
{3}{B}: Level 3
At the beginning of your draw step, draw an additional card for each opponent who has one or fewer cards in hand.

Abyssal Persecutor

Flying, trample
You can't win the game and your opponents can't lose the game.

Archetype of Finality

Creatures you control have deathtouch.
Creatures your opponents control lose deathtouch and can't have or gain deathtouch.

Evil Eye of Orms-by-Gore

Non-Eye creatures you control can't attack.
Evil Eye of Orms-by-Gore can't be blocked except by Walls.

Manaweft Sliver

Sliver creatures you control have "{T}: Add one mana of any color."

Blistergrub

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When Blistergrub dies, each opponent loses 2 life.

Wall of Souls

Defender (This creature can't attack.)
Whenever Wall of Souls is dealt combat damage, it deals that much damage to target opponent or planeswalker.

Fangs of Kalonia

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on each creature that had a +1/+1 counter put on it this way.
Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Blood Tithe

Each opponent loses 3 life. You gain life equal to the life lost this way.

Conclave Sledge-Captain

Backup 1, backup 1, backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following abilities until end of turn. Each backup ability triggers separately.)
Trample
Whenever this creature deals combat damage to a player, put that many +1/+1 counters on it.

Wall of Limbs

Defender (This creature can't attack.)
Whenever you gain life, put a +1/+1 counter on Wall of Limbs.
{5}{B}{B}, Sacrifice Wall of Limbs: Target player loses X life, where X is Wall of Limbs's power.

Contortionist Troupe

Contortionist Troupe enters with X +1/+1 counters on it.
Coven — At the beginning of your end step, if you control three or more creatures with different powers, put a +1/+1 counter on target creature you control.