msem-instigator

Flying, trample, haste
Whenever you activate an ability of a nonland permanent, you may have Ilieth, Transcendent deals 2 damage to target creature.
{2}{R}: Creatures you control get +2/+0 until end of turn.

Vigilance
When Illari, Martyrized Tyrant enters, tap all other nonbasic permanents.
Players can't untap more than one nonbasic permanent during each of their untap steps.
When Illari dies, untap all permanents you control and you gain 5 life.

Flying
When Imperator Namuzzar enters, search your library for an artifact or enchantment card, reveal it, put it into your hand, then shuffle.
Civilized — Lammasu you control get +2/+2 and have hexproof as long as you control an artifact, a creature, and an enchantment.

First strike, vigilance
Partner with Commander Hyctaleon (When this creature enters, target player may put Commander Hyctaleon into their hand from their library, then shuffle.)
At the beginning of your upkeep, you may search your library for a Soldier card, reveal it, put it into your hand, then shuffle.

Reach
Imperious Ram can't be blocked by more than one creature.

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.)

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.

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.

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{1}: Target creature in Indomitable Anchorite's pack gains indestructible until end of turn. (Two or more creatures you control with equal power are in a pack.)

When Ingredient Scroungers enters, if you control a creature with deathtouch, return target permanent card from your graveyard to your hand.

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

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{U}{R}: Target creature without prowess gains prowess until end of turn. Activate only if Intelligence is in your graveyard.

Flying
Morph {1}{U} (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 Ishim of the Mists is turned face up, turn all other face-up creature you control face down.

When Isle Conservator enters, if you control a legendary creature, submerge target creature an opponent controls. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Activated abilities you activate cost {3} less to activate. This effect can't reduce the mana in that cost to less than one mana.
You may spend any number of colors of mana to activate attain abilities of permanents you control.

Once each turn, when Jeffery enters or you create an Aura token, you may create an Aura Role enchantment token named Lead Role attached to target creature you control. It's all colors and has enchant creature you control and “Enchanted creature has base power and toughness 5/5, is all creature types, and has flying, vigilance, trample, lifelink, and prowess.”
Whenever an enchanted creature you control attacks, draw a card.

Flying
Once during each of your turns, for each creature you control, you may activate one of that creature's activated abilities with {T} in its cost without paying {T} and as though that creature had haste.

Trample
{1}{R}: Each attacking creature you control with trample gets +1/+0 until end of turn.

Concord — This spell costs {2} less to cast if there are four or more card types among permanents you control.
Vigilance (Attacking doesn't cause this creature to tap.)

Menace
Vanguard — Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each creature card in your graveyard.

Vigilance
When Kahroba Champion enters, creatures you control get +1/+1 until end of turn.

Flying, trample
At the beginning of your upkeep, sacrifice a creature.
Revive {2}{B}{B} ({2}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)