msem-instigator

Whenever Impetuous Impetus deals combat damage to a player, you may sacrifice a land. If you do, Impetuous Impetus deals 3 damage to that player.

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

Lionize {1}{U} ({1}{U}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following ability until end of turn. You may cast this card on a later turn from exile.)
Hexproof

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

{1}, Sacrifice a creature: Put a +1/+1 counter on Implant Scavenger and move any +1/+1 counters from the sacrificed creature onto it. It gains menace until end of turn.

Whenever Implant Tinkerer or another artifact you control enters, choose one —
• Put a +1/+1 counter on that artifact.
• Implant Tinkerer deals 1 damage to any target and you gain 1 life.

Flash
Defender
When Imposing Barricade enters, target creature doesn't untap during its controller's untap step for as long as you control Imposing Barricade.

Defender

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

Flash
First strike
When Imposing Databdara enters, return each other creature with toughness less than or equal to the number of Satrapies you control to their owners' hands.

Flying
Nonland permanents your opponents control enter tapped.
Activated abilities of permanents your opponents control that entered this turn can't be activated unless they're mana abilities.

Reach
{1}, Sacrifice a nonland permanent: Imposing Manticore deals 1 damage to each opponent.

Flying
When Imposing Sphinx enters, exile target nonland permanent an opponent controls until Imposing Sphinx leaves the battlefield.
At the beginning of your end step, if you gained life this turn, you may exile Imposing Sphinx, then return it to the battlefield under your control.

Create a 2/2 black Horror creature token.
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.”)

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.

Ferocious — At the beginning of each combat, if you control a creature with power 4 or greater, Impressible Cub gets +1/+1 until end of turn.

Enchant creature
Enchanted creature can't attack, block, or be sacrificed.

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Improbable Aim deals damage to target creature or planeswalker equal to the number of [instant and sorcery] cards in your graveyard.

You may reveal a creature card you own from outside the game and put it into your hand.
The next spell you cast this turn may be cast as though it had flash. Exile Impromptu Escapade.

Enchant creature
You may cast this spell from your graveyard if it targets a legendary creature you control.
Enchanted creature gets +2/+2 and has haste.

Flying
Vanguard — Whenever a creature you control attacks alone, it gains first strike until end of turn.

Harmony — Target creature gains indestructible until end of turn.
When Improvising Automaton enters, harmonize. (Trigger up to one harmony of one permanent you control.)

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.

Exile the top card of your library. Impulsive Action deals damage to any target equal to that card's mana value plus one. Until end of turn, you may play that card.