msem-instigator

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

{T}: Add {C}.
{T}: Add {C}{C}{C}. Spend this mana only to pay advance costs.

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.

{T}: Add {C}.
{5}, {T}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

{T}, Pay 1 life: Add {B} or {R}.
{2}, {T}, Sacrifice Industrial District and another permanent: Draw a card. Activate only during your turn.

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.

When Infested Goblin dies, choose target creature. At the beginning of your next upkeep, that creature's controller sacrifices it.

Whenever Infiltrator of the Anomalous deals combat damage to a player, add {R}. Until end of turn, you don't lose this mana as steps and phases end.

{3}, {T}: Put Ing'Wei's Crystal Top on top of your library. Scry 3, then draw a card.

Whenever you cast a spell, untap Inglorious Blaze.
{T}: Inglorious Blaze deals 1 damage to target player or planeswalker.

{T}: Add one mana of any color.
Whenever you tap Ingrained Virago for mana, each opponent loses 1 life.

Indestructible
{2}{B}, Exile two cards from your graveyard: Each opponent loses 2 life and you gain 2 life.

Put a +1/+1 counter on target creature.
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.)

Target creature gains lifelink until end of turn. Untap that creature.
Inscribe {1}{W} ({1}{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.)

Draw a card.
Inscribe {1}{U} ({1}{U}: 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.)

Whenever Inquisitive Guardian deals combat damage to an opponent, you may exile a nonland card from your graveyard. If you do, draw a card.
{U}: Inquisitive Guardian gains flying until end of turn.

Graft 1 (This creature enters with a +1/+1 counter on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{T}: Add {C}.