msem-instigator

When Forlorn Murklurker dies, submerge the top card of your library. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

When Fleshwrithe Ghoul enters, each player sacrifices a creature.
Revive {4}{B} ({4}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

{B}: Fetid Nibbler gains deathtouch until end of turn.

First strike
When Engulfing Incubus enters, you may submerge target nontoken creature an opponent controls. When Engulfing Incubus is no longer on the battlefield, turn that card face up. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Flying
When Emissary of the Wicked enters, you lose 4 life.
Revive {2}{B}{B} ({2}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Menace
Whenever Dragon's Twisted Shadow attacks and isn't blocked, it gets +4/+0 until end of turn.

Target player discards two cards.
Ferocious — That player discards two cards at random instead if you control a creature with power 4 or greater.

Cast this spell only if each graveyard has a creature card in it.
Each player puts a creature card in their graveyard of an opponent's choice onto the battlefield.

When Diseased Prophet enters, each opponent loses 1 life.
Revive {B} ({B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

As an additional cost to cast this spell, sacrifice a creature.
Create a 5/5 black Demon creature token with flying. You lose 2 life.

{B}, Sacrifice another creature: Deranged Apothecary gains indestructible until end of turn.

As an additional cost to cast this spell, sacrifice a creature.
All creatures get -X/-X until end of turn, where X is the sacrificed creature's power.

Target creature gets -3/-2 until end of turn.

Target opponent loses 2 life and you gain 2 life. If you control a Wizard, instead that player loses 4 life and you gain 4 life.

Menace
Whenever a creature an opponent controls dies, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Flying
Whenever Yawning Crane deals combat damage to an opponent, target tapped creature that player controls doesn't untap during its controller's next untap step.

Whenever Whitepeak Channeler deals combat damage to a creature, tap that creature. That creature doesn't untap during its controller's next untap step.

Flying
Welkin Tern can block only creatures with flying.

Create two Idol tokens, then counter target spell unless its controller pays {1} for each Idol you control. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

When Warrior's Perspective enters, invigorate 1. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)
Whenever a creature you control with a +1/+1 counter on it becomes tapped, you may draw a card. If you do, discard a card.

Invigorate 1, then untap each creature you control with a +1/+1 counter on it. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)

Return target creature to its owner's hand. That player can't cast spells with the same name as that creature during their next turn.

Target creature gets -9/-0 until end of turn. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

When Undead Archivist enters, return target instant or sorcery card from your graveyard to your hand.
Revive {5}{U} ({5}{U}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Create two 1/1 blue Bird creature tokens with flying and “When this creature dies, draw a card.”