msem-instigator

At the beginning of your upkeep, reveal the top card of your library. Any opponent may have Insurgent Ballads deal damage to them equal to that card's mana value. If a player does, put that card on the bottom of your library. Otherwise, put it into your hand.

Exile the top card of your library. Until end of turn, you may play that card. If that card is an instant or sorcery card, it costs {2} less to cast this turn.

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.

Whenever a +1/+1 counter is put on a creature you control, scry 1.
Each creature you control with a +1/+1 counter on it has lifelink.

Whenever a creature enters, it deals damage equal to its power to any target of its controller's choice.
When Interplanar Raid enters, you may aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

Flying, ward {2}
Intisuyu's Masterpiece gets +X/+X, where X is the number of artifacts and/or enchantments you control.

Whenever you tap a land for mana, add one mana of any type that land produced.
Sacrifice Into Strange Territories: Untap up to two lands.

If a card would be put into your graveyard from anywhere, exile it instead.
If you would draw a card, return two cards from your graveyard to your hand instead. If you can't, you lose the game.

Choose one or both —
• Create two 1/1 white Soldier creature tokens. They gain haste until end of turn.
• Create an 8/0 green Scorpion creature token with trample.

When Into the Unknown enters, create two 1/1 Scout creature tokens that are all colors.
Whenever a land you control enters, if it doesn't have the same name as another land you control, put a +1/+1 counter on each creature you control.

Flying
When Intrepid enters, search your library for a land card, reveal it, put it into your hand, then shuffle.
Wanderlust — {0}: Intrepid becomes an artifact creature until end of turn. Activate only if you control four or more differently named lands.

At the beginning of combat on your turn, create a 1/1 blue and red Pirate creature token with haste. That token attacks this combat if able.
Whenever Intrepid Captain attacks, other attacking Pirates you control get +1/+0 until end of turn.

({T}: Add {U}.)
Inundated Sanctuary enters tapped with two sanctum counters on it.
{T}, Remove a sanctum counter from Inundated Sanctuary: Add {W} or {B}.

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.

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.