msem-instigator

Flying
When Illusionary Steed becomes the target of a spell or ability, sacrifice it.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. Mill three cards.

Shuffle any number of cards from your graveyard into your library.
Scry 1, then draw a card.

Imitator of Drakes has flying as long as it has a +1/+1 counter on it.
{2}{U}: Put a +1/+1 counter on Imitator of Drakes.

At the beginning of each opponent's end step, that player gets a poison counter unless damage was dealt this turn.

Indestructible
Immortal Child can't block creatures with greater power.

Enchant creature
When Impassioned Craze enters, draw a card.
Enchanted creature has “{R}: This creature gets +1/+0 until end of turn.”

Draw a card.
Civilized — Instead draw two cards if you control an artifact, a creature, and an enchantment.

Exile target artifact or enchantment. Its controller creates a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Create X 1/1 colorless Spirit creature tokens.
5 | Put a +1/+1 counter on each creature you control.

First strike
Art of war — At the beginning of your end step, if Imperial Kensai dealt damage to an opponent this turn, you may pay 1 life. If you do, put a +1/+1 counter on Imperial Kensai.

As long as Imperial Proclaimer is on the battlefield, it has all names of nonlegendary creature cards in addition to its name.

At the beginning of each upkeep you may pay {W}. If you do, tap target creature.

{U}, Sacrifice Imperious Nixie: Return target creature to its owner's hand.

Enchant creature
When Impish Delights enters, draw a card.
Enchanted creature gets +2/+0.

Look at target player's hand. You may choose a nonland card from it. If you do, that player reveals that card, puts it on the bottom of their library, then draws a card.

When Improvisionist enters, if it was the second spell you cast this turn, exile the top card of your library. You may play that card until the end of your next turn.

Advance {1}{R}{R} (Cast this for {1}{R}{R} to advance it as it enters. {1}{R}{R}: Advance this as a sorcery.)
Whenever Impulse Module enters or advances, put a charge counter on it, then exile a card from the top of your library for each charge counter on it. Until your next turn, you may play one of those cards.

Enchant creature
Enchanted creature has “Whenever this creature attacks, if there are at least two other attacking creatures, this creature gains +2/+2 until end of turn.”

Target creature you control gets +2/+2 until end of turn.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Each opponent loses 1 life and you gain 1 life. Surveil 2.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Spells and abilities you control that target Inconspicuous Sheep cost {1} less.
As long as Inconspicuous Sheep is enchanted or equipped, they're a 3/3 legendary Sheep Rogue named Agent S.

Create a tapped colorless Powercell artifact token with “{T}: Add {C}.” It doesn't untap during its controller's next untap step.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets -1/-1.
Whenever enchanted creature attacks, its controller loses 2 life.

Whenever Infernal Barrier is dealt damage, it deals 1 damage to each opponent.