msem-instigator

Recruit X times. You lose X life. (To recruit, create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Menace
Once during each of your turns, when you sacrifice a permanent, you may put a +1/+1 counter on Assimilated Runner.

Target player sacrifices a creature or planeswalker.
Flashback {4}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

When Astrid, Disgruntled Princess enters, destroy target creature with mana value less than or equal to the number of Warriors you control.

Destroy target creature.

Target player reveals their hand. You choose a nonland card from it. That player discards that card. Each player loses 1 life.

When Augmented Alchemist enters or dies, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

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

{2}: Avaricious Ghul gets +1/+1 until end of turn. If mana from a Treasure was spent to activate this ability, put a +1/+1 counter on Avaricious Ghul instead.

Deathtouch
Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Avatar of Amosis enters, if tribute wasn't paid, you may destroy target creature.

Create a 5/3 black Horror creature token.
Flashback {1}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Pressure {3}{B}{B} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Each player sacrifices a creature. Put a creature card from a graveyard onto the battlefield under your control.

Target opponent shuffles a card from their hand into their library.

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

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Back-Alley Vandal desecrates a permanent, put a +1/+1 counter on Back-Alley Vandal.

Satrapies you control have “{2}, {T}, Pay 1 life: Draw a card.”
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

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.

Target tapped creature gets -3/-3 until end of turn.

Deathtouch
When Backstage Comic enters, target player discards a card.

Lifelink
Whenever Backstage Prompter deals combat damage to a player, put a +1/+1 counter on it.

Exile target creature or planeswalker. You gain 4 life.

Scry X, then purge X times. You lose X life. (To purge, exile two cards that share a type from graveyards. If you do, draw a card.)

When Bal's Descent enters, each player sacrifices a creature, discards two cards, and mills three cards.
{1}{B}{B}: Transform Bal's Descent. Activate only if your fealty to Swamps is five or greater.