Partner with Ukkima, Stalking Shadow (When this creature enters the battlefield, target player may put Ukkima into their hand from their library, then shuffle.) Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.

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

When Fractal Harness enters the battlefield, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it and attach Fractal Harness to it. Whenever equipped creature attacks, double the number of +1/+1 counters on it. Equip {2}

{T}: Add {C}{C}.

Equipped creature gets +2/+2 and has protection from green and from white. Whenever equipped creature deals combat damage to a player, exile up to one target creature you own, then search your library for a basic land card. Put both cards onto the battlefield under your control, then shuffle. Equip {2}

Equipped creature gets +2/+2 and has protection from white and from blue. Whenever equipped creature deals combat damage to a player, put a +1/+1 counter on a creature you control, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.) Equip {2}

Benevolent Hydra enters the battlefield with X +1/+1 counters on it. If one or more +1/+1 counters would be put on another creature you control, that many plus one +1/+1 counters are put on it instead. {T}, Remove a +1/+1 counter from Benevolent Hydra: Put a +1/+1 counter on another target creature you control.

Genomic Enhancement — {T}: Add one mana of any color. If this mana is spent to cast a creature spell, that creature enters the battlefield with an additional +1/+1 counter on it.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever Cold-Eyed Selkie deals combat damage to a player, you may draw that many cards.

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

When Deepglow Skate enters the battlefield, double the number of each kind of counter on any number of target permanents.

Flying, first strike Whenever Drana, Liberator of Malakir deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

Evolve (Whenever a creature enters the battlefield under your control, 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 Fathom Mage, you may draw a card.

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.

Reach Modified creatures you control have trample. (Equipment, Auras you control, and counters are modifications.) Whenever a modified creature you control deals combat damage to a player, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Each other creature you control enters the battlefield with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

Other green creatures you control get +1/+1. Other blue creatures you control get +1/+1. Untap all green and/or blue creatures you control during each other player's untap step.

When Oran-Rief Ooze enters the battlefield, put a +1/+1 counter on target creature you control. Whenever Oran-Rief Ooze attacks, put a +1/+1 counter on each attacking creature with a +1/+1 counter on it.

Partner with Toothy, Imaginary Friend (When this creature enters the battlefield, target player may put Toothy into their hand from their library, then shuffle.) If one or more counters would be put on a permanent your team controls, that many plus one of each of those kinds of counters are put on that permanent instead.

Graft 3 (This creature enters the battlefield with three +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.) {2}: Target creature with a +1/+1 counter on it gains shroud until end of turn. (It can't be the target of spells or abilities.)

Reyhan, Last of the Abzan enters the battlefield with three +1/+1 counters on it. Whenever a creature you control dies or is put into the command zone, if it had one or more +1/+1 counters on it, you may put that many +1/+1 counters on target creature. Partner (You can have two commanders if both have partner.)

When Rishkar, Peema Renegade enters the battlefield, put a +1/+1 counter on each of up to two target creatures. Each creature you control with a counter on it has "{T}: Add {G}."

Flying, trample When Roalesk, Apex Hybrid enters the battlefield, put two +1/+1 counters on another target creature you control. When Roalesk dies, proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Flying, trample When Tanazir Quandrix enters the battlefield, double the number of +1/+1 counters on target creature you control. Whenever Tanazir Quandrix attacks, you may have the base power and toughness of other creatures you control become equal to Tanazir Quandrix's power and toughness until end of turn.

Flying Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.) As long as Thundering Mightmare is paired with another creature, each of those creatures has "Whenever an opponent casts a spell, put a +1/+1 counter on this creature."

Partner with Pir, Imaginative Rascal (When this creature enters the battlefield, target player may put Pir into their hand from their library, then shuffle.) Whenever you draw a card, put a +1/+1 counter on Toothy, Imaginary Friend. When Toothy leaves the battlefield, draw a card for each +1/+1 counter on it.

{G}{U}, {T}: Double the number of each kind of counter on target artifact, creature, or land.

Trample, haste If you would put one or more counters on a permanent or player, put twice that many of each of those kinds of counters on that permanent or player instead. If an opponent would put one or more counters on a permanent or player, they put half that many of each of those kinds of counters on that permanent or player instead, rounded down.

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, put a +1/+1 counter on this creature. It gains deathtouch and indestructible until end of turn."

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.

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

Hideaway 5 (When this enchantment enters the battlefield, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.) At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if you control a creature with power 7 or greater, you may play the exiled card without paying its mana cost.

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.

{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.

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

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

Counter target spell.

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

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

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.)

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on that creature.

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.) Destroy target artifact or enchantment.

Counter target noncreature spell.

Destroy target artifact or creature. It can't be regenerated.

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Exile target artifact or enchantment. Put X +1/+1 counters on target creature you control, where X is the mana value of the permanent exiled this way.

Strive — This spell costs {1}{G} more to cast for each target beyond the first. Choose any number of target creatures. Double the number of +1/+1 counters on each of them.

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

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

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

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

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

({T}: Add {G}.)

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

({T}: Add {U}.)

Llanowar Reborn enters the battlefield tapped. {T}: Add {G}. Graft 1 (This land enters the battlefield with a +1/+1 counter on it. Whenever a creature enters the battlefield, you may move a +1/+1 counter from this land onto it.)

{T}: Add {C}. {G}{U}, {T}: Put a +1/+1 counter on each creature that entered the battlefield this turn.

{T}: Add {C}. {1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Oran-Rief, the Vastwood enters the battlefield tapped. {T}: Add {G}. {T}: Put a +1/+1 counter on each green creature that entered the battlefield this turn.

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

({T}: Add {U} or {B}.) Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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

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

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

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

Each player chooses a nonland permanent they control. Return all nonland permanents not chosen this way to their owners' hands. Then you draw a card for each opponent who has more cards in their hand than you.

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.) Draw a card.

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

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.

Destroy all creatures. They can't be regenerated.

Cleave {1}{B}{B}{G} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.) Search your library for a [basic land] card, [reveal it,] put it into your hand, then shuffle.

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

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

Look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

Scry 2, then draw a card. (To 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.)

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying. Foretell {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.)

({U/P} can be paid with either {U} or 2 life.) Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)