msem-instigator

Whenever a creature enters the battlefield under your control, if it wasn't cast from your hand, you may mill a number of cards equal to its mana value. If you do, you may return a noncreature card milled this way from your graveyard to your hand.

Whenever you cast your second spell each turn, each opponent loses 1 life and you gain 1 life.

Flying
Whenever you cycle Seraph of the Stage or it attacks, audition for white. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Cleric Role giving 2/2 and lifelink. Roles replace older ones.)
Basic landcycling {1}{W} ({1}{W}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

Exile two target cards from your graveyard. If they share a card type, draw a card. (Then exile this card. You may cast the creature later from exile.)

When Shadowbinder Touka enters the battlefield or attacks, exile up to one target creature card from a graveyard.
You may play creature cards exiled with Touka.
Sacrifice another creature: Add two mana in any combination of colors. You can't spend this mana to cast spells from your hand. If this mana is spent to cast a creature spell, that creature enters the battlefield with a finality counter on it.

Discard a card, then draw a card.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “III—You may cast a copy of this card from exile without paying its mana cost.”)

Shining Showstopper deals 5 damage to any target. Audition for red. (Create a 1/1 Construct Actor creature token, a Warrior Role giving 3/2 and trample, or a Wizard Role giving 2/2 and prowess. Roles replace older ones.)

Flash
Whenever you cast Siflir, Elder Pawn or another spell, if you paid an alternate or additional cost to cast it, draw a card.
Wander {3}{U}{U} (You may cast this from the battlefield for its wander cost.)

You gain hexproof until end of turn.
Prevent all damage that would be dealt to you this turn.

Return target creature card from your graveyard to your hand.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “III—You may cast a copy of this card from exile without paying its mana cost.”)

Flying
At the beginning of your upkeep, sacrifice Skyward Dreamers unless you remove a counter from a permanent you control.

When Smirk enters the battlefield, add the top two cards of your library to your evil plan. (Look at them, then exile them face-down. You may pay {7} once a turn as a sorcery to cast any number of cards in your evil plan without paying their mana costs.)
Whenever you cast your second spell each turn, you draw a card and you lose 2 life.

Prowess, trample
During your turn, each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost plus “Pay X life, where X is this card's mana value.”

{T}: For each color among enchantments you control, add one mana of that color.
{2}{G}{G}, Sacrifice Sower of Seeds: Shuffle any number of enchantment cards from your graveyard into your library. Create an X/X black Horror creature token, where X is the number of enchantment cards shuffled into your library this way.

Whenever Sower of Virulent Thoughts attacks, you may return a creature you control to its owner's hand. If you do, put a +1/+1 counter on target creature you control.

Flying
When Spectre of Terror deals combat damage to a player, that player discards a card.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Flying, ward {3}
Whenever Sphinx of Myriad Futures attacks, look at the top three cards of your library and reveal one of them. The defending player may have you put the revealed card into your hand. If they don't, put the other two cards into your hand. Then put the remaining cards into your graveyard.

When Spoiled Prince enters the battlefield, each player sacrifices a creature with the greatest power among creatures they control.

Whenever a permanent you control leaves the battlefield, if it had counters on it, you may put those counters on Stage Magician.
At the beginning of your end step, you may move any number of counters from Stage Magician onto target permanent you control.

Create a 3/3 black Demon Horror creature token.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “III—You may cast a copy of this card from exile without paying its mana cost.”)

Whenever you gain life, each opponent loses 1 life.

When Stolen Light enters the battlefield, exile target nonland permanent an opponent controls until Stolen Light leaves the battlefield.
{W}{U}{B}{R}{G}: Put a permanent card exiled with Stolen Light onto the battlefield under your control. It's a 3/3 Horror creature in addition to its other types.

Whenever another creature enters the battlefield under your control, put your choice of a +1/+1 counter, a trample counter, or a haste counter on it.

Choose one or both —
• Audition for green. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Warrior Role giving 3/2 and trample. Roles replace older ones.)
• Target creature you control fights target creature you don't control.

You may have Strikebreaker enter the battlefield as a copy of a non-Aura enchantment you control, except it's a 2/2 Construct Actor creature in addition to its types.