msem-instigator

When Sword of the Heavens enters, attach it to target creature you control.
Equipped creature gets +2/+2 and has flying, vigilance, and “Whenever this creature attacks, you may search your library and/or graveyard for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.”
Equip {3}

Choose one —
• Target attacking creature gets +2/+2 until end of turn.
• Destroy target artifact.

Destroy target creature.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Ravenous Hollow enters tapped.
{T}: Add {B} or {R}.
{2}{B}{R}: Until end of turn, Ravenous Hollow becomes a Wolf creature with first strike in addition to its other types.
Scavenge {2}{B}{R}

Discard a card, then draw a card.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Flying
Whenever a permanent you control becomes the target of a spell or ability you don't control, choose one —
• Create a 3/3 red Manticore creature token.
• Create two Treasure tokens.
• Draw a card.

Target creature gets -2/-0 until end of turn. If that creature is tapped, draw a card.

When Life from Death enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Whenever a nontoken creature you control dies, create a 1/1 green Saproling creature token.

Whenever Mortified Medium or another creature enters, you gain 1 life.
As long as you have at least 10 life more than your starting life total, Mortified Medium gets +4/+4 and has flying.

When Sacrifice to Setar dies, surveil X, where X is the amount of damage dealt to them this turn. Draw a card. Then if X is 3 or greater, you may return Sacrifice to Setar to the battlefield transformed.

When you cast a creature spell, sacrifice Gemini Cast. If you do, create a token that's a copy of that spell, except the token isn't legendary.

Hymn of Fury deals 1 damage to each creature, then each creature you control gains haste and double strike until end of turn.

Search your library for a creature card, an instant card and a sorcery card and reveal them. Put one of those cards into your hand, exile the rest, then shuffle.

Target player discards two cards.

Prowess
Gusma's Emissary gets +1/+1 as long as you control a black or green permanent.

Search your library for a creature card with haste, one with reach, one with trample, and one with vigilance, each with different names and reveal them. An opponent chooses two of those cards. Put the chosen cards into your graveyard and the rest into your hand. Then shuffle.

When Moth-Heart Husk dies, create a 1/1 black Spirit creature token with flying.
Revive {3}{B} ({3}{B}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Submerge all creature cards in graveyards. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Counter target spell unless its controller pays {X}. If they do, you draw half X cards, rounded down.

Flash
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{W}{B}: Kirishima's Escort gets +1/+1 and gains first strike until end of turn.

If one or more -1/-1 counters would be put on a creature an opponent controls, put twice that many -1/-1 counters on it instead.

Flying, lifelink
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Recreator of Myths attacks, you may cast target instant or sorcery spell from your graveyard. If you do, exile that card instead of putting it into your graveyard as it resolves.

Return target creature card with mana value 3 or less from your graveyard to the battlefield.

Return target nonland permanent to its owner's hand.
Dominance — If you control the creature with the greatest power or tied for the greatest power, you may put that permanent on top of its owner's library instead.

When Journey through Uwaito enters, draw a card, then choose a creature card name.
Whenever a creature you control with the chosen name dies, each opponent discards a card.