msem-instigator

Stampede — Whenever Cloud's Roar Avenger and a creature with greater power attack, tap up to one target creature.

Rakkiri Pathblazer gets +2/-1 as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Creatures you control get +1/+1 until end of turn.
Inscribe {2}{W} ({2}{W}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flying
Morph {2}{W}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When you turn Wardwing Seraph face up, untap it.

Target creature you control gets +X/+0 until end of turn. It deals damage equal to its power to up to one target creature.

As an additional cost to cast this spell, discard a card.
Draw two cards. Gift of the Phoenix deals 2 damage to you.

Whenever a land enters the battlefield under your control, create a 1/1 white Soldier creature token with vigilance.
{4}{G}{W}, Sacrifice Protect the Farm: Creatures you control get +2/+2 until end of turn.

Motivate 3 (When this creature enters the battlefield, you may motivate target creature with less power than this by putting three +1/+1 counters on it.)
When General Merthilios motivates a creature, that creature gains first strike, trample, and haste until end of turn.

Draw a card.

{1}{G}: Night's Guard gets +2/+2 until end of turn. Activate only once each turn.

Whenever a permanent you control leaves the battlefield, put a +1/+1 counter on Royal Doctor.
When Royal Doctor leaves the battlefield, you gain life equal to its power.

Target player reveals their hand. You choose a nonland card from it. That player discards that card. Each player loses 1 life.

Cliffside Entrance enters the battlefield tapped unless you have 15 or less life.
{T}: Add {R} or {W}.

Surveil 1, then draw a card. You lose 1 life.
Flashback—{B}, Sacrifice a creature. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flash
When Brightsouled Guardian enters the battlefield, return up to one target nonland permanent to its owner's hand.

Whenever you cast an Adventure spell, put a +1/+1 counter on Adventurer Extraordinaire.

Swirling Dragonfire deals damage to any target equal to the number of instant and sorcery cards in your graveyard.

Enchant land
When Grace of Timber enters the battlefield, put a +1/+1 counter on target creature you control.
Enchanted land has “{T}: Add two mana of different colors.”

Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip {2}

({T}: Add {U}.)
Cloudbank enters the battlefield tapped.
When Cloudbank enters the battlefield, target creature gains flying until end of turn.

Spells cost {1} more to cast for each colored mana symbol in their mana cost beyond the first. (For example, a spell with mana cost {W}{W} would cost {1}{W}{W} to cast.)

At the beginning of your upkeep, create a 1/1 green Saproling creature token.
Whenever a creature you control dies, put a +1/+1 counter on Heart of Spores.
{X}{G}: Move X +1/+1 counters from Heart of Spores onto target creature. Activate only as a sorcery.

Meletian Trireme can't be blocked by creatures with power 2 or less.
Whenever Meletian Trireme enters the battlefield or deals combat damage to a player or planeswalker, scry 1, then draw a card.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Attentive Glider gets +2/+2 and has flying as long as you cast an Adventure spell or a permanent you controlled explored this turn.