msem-instigator

Flying
Morph {4}{R}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Ishim of Devilry is turned face up, put a +1/+1 counter on it, then each opponent loses 2 life and you gain 2 life.

Menace, lifelink
Whenever Jonah of the Spellbane deals combat damage to a player, destroy target creature or planeswalker, then scry 1.

Sacrifice Kemono-no-Oni: Return target creature card from your graveyard to your hand.

Art of war — At the beginning of your end step, if Kurayami Butcher dealt damage to an opponent, you may destroy target creature that was dealt damage this turn.

Whenever another nontoken creature you control dies, you may exile it. If you do, create a 2/2 colorless Spirit creature token.

Menace
Whenever a nontoken creature you don't control dies, create a token that's a copy of that creature except it's a colorless Spirit. Exile it at the beginning of your next end step.

When Last-Thought Feeder dies, fateseal 2. (To fateseal 2, look at the top two cards of an opponent's library, then put any number of them on the bottom of that player's library and the rest on top in any order.)

When Lunar Defractor enters, each player discards a card.
Revive {5}{B}{B} ({5}{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.)

Flying
{1}, Sacrifice a creature: Mahara Angel gets +1/+1 until end of turn.

Whenever Ming Fleet Privateer attacks, put a menace counter on target creature in its pack. (Two or more creatures you control with equal power are in a pack.)

Deathtouch
Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)

Nameless Throng can't block.
{1}{B}, Exile an artifact or enchantment card from your graveyard: Return Nameless Throng from your graveyard to the battlefield.

Neckbreaker Viking gets +1/+0 and has menace as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Each player loses 1 life.
[Lore III] Create a 1/1 black Harpy creature token with flying.

{B}, Discard a card: Post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

Once during each of your turns, you may cast a legendary creature or planeswalker spell from your graveyard.
Sacrifice Pallid Herald: Exile up to three target cards from graveyards.

{W}: Parish Custodian gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

When Profaner of Souls enters, you may return target creature card with mana value 2 or less from your graveyard to the battlefield.
Revive {6}{B} ({6}{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.)

Whenever Qalami Barbarian attacks, you may discard a card. If you do, it gets +1/+2 and gains menace until end of turn.

Whenever Quick-Witted Slayer deals combat damage to a player, you draw a card and you lose 1 life.

Whenever Ravencaller or another creature enters from your graveyard, create a 1/1 blue Bird creature token with flying.

When Razorshell Marauder enters, you may sacrifice a land or exile a land card from your graveyard. When you do, target creature gets -1/-1 until end of turn and can't block this turn.

Whenever Recurring Abomination deals combat damage to an opponent, you may put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.
{4}{B}{B}: Return Recurring Abomination from your graveyard to the battlefield tapped.

At the beginning of your upkeep, if a library has twenty or fewer cards left in it, return Returned Explorer from your graveyard to the battlefield tapped.

As long as there are three or more creature cards in your graveyard, Returned Minotaur gets +1/+1 and has menace.