msem-instigator

Flying
Morph {3}{U}{R} (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 Punishment is turned face up, put a +1/+1 counter on it, then untap another target tapped creature. Ishim of Punishment deals 3 damage to that creature.

Flying
Morph {3}{G}{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 Tempest is turned face up, put a +1/+1 counter on it, draw three cards, then discard two cards.

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.

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
{2}{W}{B}: Ishim's Meddling becomes a 4/4 Angel creature with flying and vigilance until end of turn.

Whenever you cast a noncreature spell, scry 1.
{3}{U}, Exile an instant or sorcery card from your graveyard: Draw a card.

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.)

As Isochron Wand enters, you may exile an instant or sorcery card with mana value 1 from your hand.
At the beginning of your upkeep, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost if the spell's mana value is 1.

Enchant permanent
Enchanted permanent loses all abilities except for mana abilities and has no name.

({T}: Add {G}.)
Isolated Cloister enters tapped.
{G}, {T}, Reveal a green card from your hand: You gain 1 life.

Trample
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Isolated Guardian. It loses this ability and gains “Whenever this attacks, put two +1/+1 counters on each of up to two target creatures.”

Menace
Whenever Issbarren Creeper deals combat damage to a player, draw a card, then discard a card.

Flying, haste
Dominance — At the beginning of combat on your turn, if you control the creature with the greatest power or tied for the greatest power, you may pay {1}{R}. If you do, return Issbarren Phoenix from your graveyard to the battlefield.

Flash
When Issbarren Warden enters, exile target token.

Menace (This creature can't be blocked except by two or more creatures.)
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Haste (This creature can attack and {T} as soon as it comes under your control.)

First strike (This creature deals combat damage before creatures without first strike.)
Whenever a creature you control becomes blocked by a creature, Itava Scourge deals 1 damage to that creature's controller.

Menace (This creature can't be blocked except by two or more creatures.)
Itava Warshrieker attacks each combat if able.

Trample, vigilance
You may cast Iteration Devourer from your graveyard by exiling seven other cards from your graveyard in addition to paying its other costs.

Artifact creatures you control get +1/+1.
{1}{U}, Discard an artifact card: Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them and create a Masterpiece token of your choice.)
Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

Once during each of your turns, when you cast an instant or sorcery spell, you may create a Function token with that spell's effects. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell. A spell's effects includes added functions.)

Whenever you cast a creature or planeswalker spell, if mana produced by a nonland permanent was spent to cast it, it gains trample and haste until end of turn.
{T}: Add {R} or {G}.

Deathtouch
As long as there are five or more different creature types among creatures you control, Itinerant Stalker gets +1/+0 and must be blocked if able.

Paranoia—Reappropriate white. (You may cast this spell by exiling two white cards from your hand and/or graveyard when a permanent you control leaves the battlefield.)
When Ivenge's Evangel enters, create a 1/1 white Cleric creature token and you gain 1 life.