msem-instigator

At the beginning of each upkeep you may pay {W}. If you do, tap target creature.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{1}, Sacrifice another creature: Imperious Aristocrat gains indestructible until end of turn. If you're in a renaissance, each opponent loses 2 life and you gain 2 life.

{1}, Sacrifice a creature: Put a +1/+1 counter on Implant Scavenger and move any +1/+1 counters from the sacrificed creature onto it. It gains menace until end of turn.

Ferocious — At the beginning of each combat, if you control a creature with power 4 or greater, Impressible Cub gets +1/+1 until end of turn.

Flying
Vanguard — Whenever a creature you control attacks alone, it gains first strike until end of turn.

Harmony — Target creature gains indestructible until end of turn.
When Improvising Automaton enters, harmonize. (Trigger up to one harmony of one permanent you control.)

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.

{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.

Haste
When Inciter of Spirits Scorned enters, return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains haste. Sacrifice it at the beginning of the next end step.

Haste
When Inciting Bard enters, other creatures you control get +1/+0 and gain haste until end of turn.

Sacrifice Indomitable Bear: Creatures you control gain indestructible until end of turn.

When Indomitable Duo enters, choose up to two creature card names.
Whenever Indomitable Duo attacks, put a +1/+1 counter on each creature you control with a name chosen by Indomitable Duo.

{W}{B}, Shuffle Inexorable Explorer into your library: Return target creature card from your graveyard to the battlefield.
{W}{B}, Sacrifice a creature: Return Inexorable Explorer from your graveyard to the battlefield tapped.

When Inexperienced Martyr dies, each opponent loses 1 life.

When Infamous Bilgecaptain enters, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.)
Other Pirates you control get +1/+1.
At the beginning of your end step, you may put a Pirate card with mana value less than or equal to the number of artifacts you control from your hand onto the battlefield.

Whenever you cast an instant or sorcery spell, Infernal Immolator deals 2 damage to each opponent.

Hexproof
Whenever another creature you control becomes the target of a spell an opponent controls, you may submerge that creature. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)
{1}{U}{U}: Turn target face-down creature you control face up.

Whenever you cast a spell, untap Inglorious Blaze.
{T}: Inglorious Blaze deals 1 damage to target player or planeswalker.

Flying
Attain {4}{B} ({4}{B}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

At the beginning of your end step, if you lost 2 or more life this turn, create a 1/1 black Bird creature token with flying. If you lost 4 or more life this turn, instead create a 3/3 black Cat creature token with deathtouch. If you lost 6 or more life this turn, instead create a 5/5 black Golem creature token with trample.

Whenever Inkwell Daggers enters or attacks, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

{T}, Sacrifice a land: Destroy target land.

Flying
When Inspirational Beacon enters, you gain 3 life.

Harmony — Target creature gets +2/+2 until end of turn.
When Inspiring Band enters, harmonize. (Trigger up to one harmony of one permanent you control.)

{1}{W}, {T}: Other creatures you control get +1/+1 until end of turn.