msem-instigator

Counter target spell unless its controller pays {1}.

Draw X cards.
Flashback—{U}{U}{U}, Sacrifice X permanents. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Inversion of Flesh deals 5 damage to each creature and each planeswalker, and 5 damage to each player with the highest life total or tied for highest life total among players.

Hexproof
Invisible Stalker can't be blocked.

Target opponent reveals cards from the top of their library until they reveal two instant and/or sorcery cards. Exile those cards, then that player shuffles the rest into their library. You may cast cards exiled this way until end of turn, and you may cast them without paying their mana costs.

Look at the top eight cards of your library. You may put a creature card from among them onto the battlefield and exile an instant or sorcery card from among them. Put the rest on the bottom of your library in a random order. As long as that creature is on the battlefield, whenever it deals combat damage to a player, copy the exiled card and you may cast the copy without paying its mana cost.

Search your library for a Demon card or a black card with mana value 6 or greater, reveal it, put that card in your hand, then shuffle.

Codex — Little Pig; Charging Cassowary; The Lonely Hunter; Shadowlurk; Blood Constrictor. (As this enters, conjure its contents into a shuffled face-up additional library.)
You may cast Adventures of this codex's contents from your graveyard.

[+1]: Create a tapped 3/3 black Crocodile creature token with menace.
[–1]: You may cast a copy of Size Up.
[–7]: Each land you control becomes a 3/3 Crocodile creature and gains menace and haste until end of turn.

Flying, lifelink
Whenever another creature you control attacks, until end of turn, that creature gets +2/+0 if it's red, +0/+2 if it's green, gains lifelink if it's white, and gains flying it if it's blue.

Flash
Deathtouch, lifelink
Whenever Irika, Wielder of Secrets deals combat damage to a player, you may pay {U/B}. If you do, you draw a card and you lose 1 life.

Flying, trample, lifelink

Indestructible
As long as your devotion to red and white is less than seven, Iroas isn't a creature.
Other creatures you control have first strike.
Whenever you attack for the first time each turn, untap all other creatures you control. After this phase, there is an additional combat phase.

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Iron Warden enters with two -1/-1 counters on it.
When Iron Warden dies, you may put its -1/-1 counters on target creature.
{R}: Iron Warden gets +1/+0 until end of turn.

Trample
At the beginning of each combat, you may have Ironhide Bellower deal 3 damage to target creature you control. If you do, Ironhide Bellower gets +3/+0 and can't be blocked by creatures with total power 3 or less until end of turn.

Whenever a creature you control leaves the battlefield, if it had counters on it, you may put one of those counters on Ironpact Marauder.
{1}{B}, Remove two counters from Ironpact Marauder: You draw a card and you lose 1 life.

Protection from mana values lower than Ironwood Elemental's power (This permanent can't be blocked, targeted, dealt damage, or enchanted by anything with mana value lower than this creature's power.)
Ironwood Elemental's power and toughness are each equal to the number of creatures you control.

Flash
As long as Iroshi entered this turn, you may activate their loyalty abilities any time you could cast an instant.
[+1]: You may return a creature you control to its owner's hand. If you do, draw a card.
[–1]: Create a 2/2 green Ninja creature token.
[–2]: Target creature you control deals damage equal to its power to target creature or planeswalker.

When Irreverent Sinscape enters, destroy up to one other target nonland permanent.
When Irreverent Sinscape dies, exile it. When you do, you may exile any number of cards from your graveyard that have four or more card types among them. If you do, return a permanent card from a graveyard to the battlefield under your control. You may repeat this process any number of times.

When Irticull's Vanguard enters, exile target nonland permanent an opponent controls until Irticull's Vanguard leaves the battlefield.
Reprocess {1}{W}{W}{W} (Cast a copy of this from your graveyard by exiling it and paying {1}{W}{W}{W}. Spend only mana from differently named sources this way.)

Flying
Morph {4}{R}{W} (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 Devilry is turned face up, put a +1/+1 counter on it, then each opponent loses 2 life and you gain 2 life.

Flying
Morph {3}{B}{G} (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 Genesis is turned face up, put a +1/+1 counter on it, then return target instant or sorcery card from your graveyard to your hand.

Flying
Morph {4}{W}{B} (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 Oblivion is turned face up, put a +1/+1 counter on it, then destroy target noncreature, nonland permanent.

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.