msem-instigator

Vanguard — Whenever a creature you control attacks alone, you may exile target instant or sorcery card from your graveyard. If you do, you may cast that spell from exile until your next turn. If that spell would be put into a graveyard, exile it instead.

Beckon Drake {2}{U}{U} ({2}{U}{U}: This noncreature Deity permanently becomes a Drake creature in addition to its other types.)
Flying
Other creatures you control with flying get +1/+1.

Whenever Supreme Mechanothurge or another artifact you control enters, up to one target artifact you control becomes a copy of another target artifact or creature you control, except it's an artifact in addition to its other types.

Flying
Whenever Swiftwing Sphinx or another creature with flying deals combat damage to an opponent, put a +1/+1 counter on that creature.

Flying
Other creatures you control with flying get +1/+1.

Flash
When this creature enters, you may return target instant or sorcery card in a graveyard or nonland permanent to its owner's hand.
Whenever this creature attacks, you may cast a spell from your hand with mana value less than this creature's power without paying its mana cost.

Flying
When Thunder Shrike enters, choose up to two target permanents. For each of those permanents, you may tap or untap it.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copies.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{3}{U}: Target creature gains slipstream until end of turn.

Flying
When Windrider Elemental enters, target creature gains flying until end of turn.

Deathtouch
Abyss Surger enters with X +1/+1 counters on it, where X is the greatest power among creature cards in your graveyard.

{2}{B}, {T}, Discard a card: Create a 2/2 black Zombie creature token. If a noncreature card was discarded this way, that token enters tapped.

When Asking Imp enters, an opponent may pay 2 life. If they do, return Asking Imp to its owner's hand.

Deathtouch
Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] You may sacrifice another creature. If you do, draw a card.
[Lore III] Remove all lore counters from Astral Leech. Each opponent sacrifices a creature.

Flying
When Augur of Bleak Horizons enters, you gain 3 life and you mill three cards.

Flash
When Axom enters, remove up to three counters from target permanent.
{2}{U}: Return Axom to its owner's hand.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever Backalley Silencer deals combat damage to a player, destroy target marked creature.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever Barrow Banshee deals combat damage to an opponent, that player discards a card at random.

Flying
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)
When Bitter Corvus enters, you may reveal the top X cards of your library, where X is Bitter Corvus' power. You may put up to one card revealed this way into your hand. You lose life equal to its mana value. Put the rest into your graveyard.

When Blood Jade Prophet enters, reveal the top three cards of your library. For each card revealed this way, you may pay 3 life. If you do, put that card into your hand. Otherwise, put it into your graveyard.

Flash (You may cast this spell any time you could cast an instant.)
When Bloodhunter Orca enters, target opponent sacrifices a creature that was dealt damage this turn.

Flash
This spell costs {2} less to cast if five or more cards are in your graveyard.

Whenever another creature you control dies, put a +1/+1 counter on Carnage Gorger.

When Carrion Sculptor enters, create a 2/2 black Zombie creature token.
{2}{B}, Sacrifice a creature: Return target creature card from your graveyard to your hand.
{1}{B}, Exile Carrion Sculptor from your graveyard: Create a tapped 2/2 black Zombie creature token.

Flying
Whenever Cavern Scourge attacks, you may exile a card from your graveyard. If you do, you gain 3 life.