msem-instigator

When Impatient Busker enters, you may put a lore counter on target Saga.

Trample
If a creature in Imperial Guardian's pack would deal damage to a permanent or player, it deals twice that much damage instead. (Two or more creatures you control with equal power are in a pack.)

Destroy target nonbasic land.

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.

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

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.

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.

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.

Enchant creature
Whenever enchanted creature deals combat damage to a player, exile the top card of your library. Until end of turn, you may play that card.

Choose target creature you control. Exile each creature you control. For each creature exiled this way, create a token that's a copy of the chosen creature, except it has haste and isn't legendary. At the beginning of the next end step, sacrifice those tokens, then return the exiled cards to the battlefield tapped.

Enchant creature
Whenever enchanted creature attacks, up to two target creatures can't block this turn. Up to one target creature blocks this turn if able.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Whenever this creature attacks, target creature blocks it this combat if able.

This spell costs {1} less to cast for each tapped creature you control.
Whenever Incarnation of Enmity attacks, each other attacking creature gets +1/+0 until end of turn.

Incendiary Flow deals 3 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.

When Incense Stoker enters, you may return target instant or sorcery card with mana value less than or equal to the number of differently named lands you control from your graveyard to your hand.

{R}, Tap two untapped artifacts you control: Incineration Expert deals 1 damage to any target.
{3}{R}, Tap eight untapped artifacts you control: Incineration Expert deals 8 damage to any target.

As a permanent you control explores an Aura, you may put it onto the battlefield attached to Inconspicuous Stowaway.
As long as Inconspicuous Stowaway is enchanted or equipped, she's a legendary 2/3 Cat Rogue named Agent C and has double strike.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever Indebted Burglar becomes blocked, defending player loses 1 life.

Enchant creature
Enchanted creature gets +3/+2 and attacks each combat if able.

Create three 1/1 red Human creature tokens with haste. Sacrifice those tokens at the beginning of the next end step.
Draw a card.

This spell can't be countered.
Inescapable Blaze deals 6 damage to any target.

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