msem-instigator

When Leija's Greenblade enters, you may pay {G}. If you do, destroy target artifact or enchantment.

{3}{G}: Put a +1/+1 counter on Lifecaller Dryad.

Each other creature you control that's an Elf or a Warrior gets +1/+1.
{2}, Sacrifice Llanowar Exemplar: Creatures you control gain indestructible until end of turn.

Whenever you sacrifice a permanent, Mischievous Maolu gets +1/+1 until end of turn and you gain 1 life.

Reach, deathtouch
When Nightshade Ambusher enters, you may pay {1}{G}. When you do, destroy target creature with flying.

Whenever you draw a card, put a +1/+1 counter on Ontarachie Dryad.
Remove a counter from Ontarachie Dryad: Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

When Ontarachie Emissary leaves the battlefield, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Overgrown Siren must be blocked if able.

Colossal 2—{1}{G}{G} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {1}{G}{G} as a sorcery: Put two +1/+1 counters on it if it has none.)
Whenever a permanent you control with a counter on it becomes the target of a spell or ability an opponent controls, draw a card.

All creatures able to block Raiun Bay Merchant do so.

When Reclamation Sage enters, you may destroy target artifact or enchantment.

When Rei's Cultivator enters, create a green Aura enchantment token named Sowing Spring attached to target land. The token has enchant land, “Enchanted land's name is Flowering Expanse” and “Whenever enchanted land is tapped for mana, add one mana of any color.”

Flash
When Scuripi Lookout enters, target creature gains hexproof until end of turn.
Whenever one or more creatures you control attack, you may return Scuripi Lookout to its owner's hand.

Vigilance
{T}: Add {G}.

Concord — {1}{G}: Until end of turn, Seadrake Rider gets +2/+3 and must be blocked if able. Activate only during your turn, only once each turn, and only if there are four or more card types among permanents you control.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Seeker of Ruins deals combat damage to a player, put a +1/+1 counter on it.

You may look at the top card of your library any time.
You may play lands from your graveyard and the top of your library.

Stray Sighthound can't be blocked by creatures with power 2 or less.
Attain {3}{G} ({3}{G}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

When Symbiotic Sprout dies, create two 1/1 green Saproling creature tokens.

As Theodore Harper, Head Librarian enters, choose Fact or Fiction.
• Fact — Permanent spells you cast cost {1} less to cast. This effect can't reduce the amount of mana a spell costs to cast to less than one mana.
• Fiction — When Theodore Harper enters, return a permanent card from your graveyard to your hand.

Reach, deathtouch

When Three Seas Squire enters, target creature or Vehicle gets +2/+1 until end of turn.

{G}, {T}: Target creature with power 4 or greater fights any number of target creatures you control.

{T}, Mill two cards: Add one mana of any color.