msem-instigator

Enchant creature
Enchanted creature gets +1/+2.
Whenever enchanted creature attacks, scry 1.

Creatures you control get +2/+1 until end of turn.

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.

Enchant creature
Whenever enchanted creature attacks, other creatures you control get +1/+2 until end of turn.

Creatures you control get +1/+1 until end of turn. Token creatures you control get an additional +1/+1 until end of turn.

Inspirited Duelist has double strike as long as it has a +1/+1 counter on it.

Target creature gets +1/+1 until end of turn for each creature token you control.
Put the bottom card of your library into your hand.

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.

Flying
{1}{W}: Exile target artifact you control. Return that card to the battlefield under your control at the beginning of the next end step.

Exile target nonland permanent.

Put a +1/+1 counter on each creature you control. Until end of turn, creatures you control gain vigilance and “When this creature dies, create a 1/1 white Human creature token.”

Improve {W} ({W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever one or more embattled creatures you control attack, create a 1/1 white Cleric creature token with lifelink. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Put a +1/+1 counter on target creature. It gains indestructible until end of turn.

Destroy target artifact or enchantment. You gain 4 life.

Enchant creature
Enchanted creature can't attack or block, can't be sacrificed, and its activated abilities can't be activated.

First strike
Whenever you cast an artifact or enchantment spell, put a +1/+1 counter on Ironclad Infantry.

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Whenever Irreguleopard deals combat damage to a player, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

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.)

Flash
When Issbarren Warden enters, exile target token.

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.

Tap an untapped creature you control: Put a loyalty counter on Ivenge, False God. Activate only once each turn.
[+1]: Exile up to one target non-Plains permanent. At the beginning of that card's owner's next upkeep, return it to the battlefield under their control.
[–2]: Exile target nonland permanent an opponent controls. They create a Plains token. (It's a basic land with “{T}: Add {W}.”)
[–10]: Exile all permanents your opponents control. For each permanent exiled this way, its controller creates a colorless Plains basic land token.

Whenever Ivory Curtain Producer attacks, if it's enchanted or you cast a spell that targeted it this turn, create a 1/1 colorless Construct Actor creature token.

Whenever you cast a white spell, choose up to X, where X is the number of white mana symbols in that spell's mana cost —
• Return target creature card with mana value 1 or less from your graveyard to the battlefield.
• Creatures target player controls get +1/+1 until end of turn.
• Target player gains 2 life.
• Tap target creature.

Vigilance
{3}{W}, {T}: Tap target creature. This ability costs {3} less to activate as long as J-7 Freeze Frame is a creature.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)