msem-instigator

Look at the top card of your library. You may put it into your graveyard. Repeat this process twice, then draw a card.

Consume Creation deals 2 damage to any target and you gain 2 life.

Whenever Consuming Doom or another enchantment you control enters, you may have target creature get -1/-1 until end of turn.
Whenever a source an opponent controls destroys an enchantment you control, that player sacrifices a creature.

When Consumption Catalyst 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 you draw a card, each opponent loses 1 life and you gain 1 life.

Deathtouch
Whenever a creature you control with deathtouch deals damage to an opponent, that player creates a black enchantment token named Blight with “At the beginning of your upkeep, you lose 1 life.”

When Contagious Host dies, each player loses 1 life.
Revive {2}{B} ({2}{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
When Cormoran, Raven Monarch enters, you may put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.

Whenever another Zombie you control enters, you may pay {1}{B}. If you do, exile target creature card from a graveyard. You gain life equal to its toughness.

{T}, Remove a +1/+1 counter from a creature you control: You draw a card and you lose 1 life.

({T}: Add {B}.)
Corpsebed enters tapped.
When Corpsebed enters, exile up to two target cards from graveyards.

Deathtouch
When Corpsecaster Mage enters, if you cast it, target creature card in your graveyard gains arise until end of turn. Its arise cost is equal to its mana cost. (Exile that card from your graveyard and pay its arise cost: Create a token that's a copy of it except it's a black Zombie in addition to its other types, has no mana cost, and can't block. Arise only as a sorcery.)

Whenever another Zombie or Demon creature you control enters, 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 target creature you control dies this turn, return it or another creature card with an equal or lesser mana value from your graveyard to the battlefield tapped.

Return target creature or planeswalker card from your graveyard to the battlefield. If that card was a creature, it's an Actor in addition to its other types.

At the beginning of your upkeep, choose one —
• You lose 1 life.
• You draw two cards and you lose 3 life.
• Search your library for a card, put it into your hand, then shuffle. You lose 5 life.

When Corrupt Warden enters, up to one target creature gets -X/-X until end of turn, where X is the number of card types among cards in your graveyard.

This spell costs {1} less to cast for each card type among cards in your graveyard.
Deathtouch

Surveil 2, then you draw a card and you lose 1 life. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
{2}{B}, Exile Corrupted Knowledge from your graveyard: Each opponent loses 2 life and you gain 2 life.

Glitch {1} (Remove one [restriction] for each time you pay the glitch cost.)
Target opponent reveals their hand. You choose a [noncreature,] nonland card [with mana value 3 or less] from among them. That player discards that card.

(Transform this if it's not attached to a creature. Pay {3}{B} as a sorcery to unattach it.)
Enchant creature you control
Corrupted Mount's rider gets +5/+4 and can't block.

Enchant creature
Enchanted creature gets +3/-2.

Whenever you cast a white spell, target player loses 2 life and you gain 2 life.
Whenever you cast a green spell, put a +1/+1 counter on Corrupted Warlord.

Enchant creature
Enchanted creature gets -3/-3 and has “At the beginning of your upkeep, you lose 3 life.”

Whenever one or more cards leave your graveyard, each opponent loses 1 life and you gain that much life.

Sacrifice a creature: Each opponent loses 1 life and you gain 1 life.
Sacrifice two creatures: Draw a card.
Sacrifice three creatures: Exile target creature or planeswalker.