msem-instigator

Target creature gets +2/+2 until end of turn. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

Flash (You may cast this spell any time you could cast an instant.)
When Gorillas in the Mist enters, prevent all combat damage that other creatures would deal this turn.

Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)

Enchant creature
When Knight's Daring enters, put two +1/+1 counters on enchanted creature.
Whenever enchanted creature deals combat damage to a player, put a +1/+1 counter on each creature you control with a +1/+1 counter on it.

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Mold Shambler enters, if it was kicked, destroy target noncreature permanent.

Mossvine Lurker has trample as long as it has a +1/+1 counter on it.

Exile a nonland card from your graveyard: For each colored mana symbol in that card's mana cost, add one mana of that color. Activate only once each turn. (For example, if the card's mana cost is {3}{G}{G}{W}, you add {G}{G}{W}.)

Defender (This creature can't attack.)
When Naturebound Druid enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Motivate 1 (When this creature enters, you may motivate target creature with less power than this by putting a +1/+1 counter on it.)
When Nroxi Beastmaster motivates a creature, that creature gains trample until end of turn.

Target creature you control gets +2/+2 until end of turn. It fights target creature with flying you don't control.

Whenever Poignant Hydra deals combat damage to a player, put a +1/+1 counter on it.
Creature spells you cast with power less than Poignant Hydra's power cost {1} less to cast.

Rammanethi Hydroshaper gets +1/+1 as long as you control an Island.
{2}{U}: Target creature blocking or blocked by Rammanethi Hydroshaper gets -1/-0 until end of turn.

Flash
Motivate 7 (When this creature enters, you may motivate target creature with less power than this by putting seven +1/+1 counters on it.)

Whenever another creature you control enters, you may change Reshaping Primordial's base power and toughness to that creature's power and toughness.

Whenever a land creature you control deals combat damage to a player, put a +1/+1 counter on it.
{1}{G}: Put a +1/+1 counter on target land you control. It becomes a 0/0 Elemental creature that's still a land.

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Reach (This creature can block creatures with flying.)
If Shadowcreep was kicked, it enters with two +1/+1 counters on it.

Flash (You may cast this spell any time you could cast an instant.)
When Stampede Instigator enters, target creature gets +2/+3 until end of turn.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever Steelhoof Battlechief attacks, another target attacking creature you control gets +2/+2 and gains trample until end of turn.

Scry 2, then reveal the top card of your library. If it's a basic land card, put it onto the battlefield tapped. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

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

As an additional cost to cast this spell, sacrifice a creature.
Put X +1/+1 counters on target creature you control, where X is the sacrificed creature's power. You gain X life.

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Vigorous Tracker enters, if it was kicked, search your library for a land card, reveal it, put it into your hand, then shuffle.

[+1]: Create a 1/1 white Soldier creature token.
[–2]: Until end of turn, target creature you control gets +3/+3 and other creatures you control get +1/+1.
[–8]: You get an emblem with “Each creature you control gets +1/+1 for each other creature you control.”

Whenever you sacrifice a creature, you may pay {B}{G}. If you do, put a +1/+1 counter on Bloodblade Mercenary and draw a card.