msem-instigator

You don't lose the game for having 0 or less life.
Whenever you're dealt damage, mill that many cards.
{B}, Pay 2 life: Put target card in your graveyard on the bottom of your library.

Enchant creature
Enchanted creature has winnow. (Damage dealt to it also causes its controller to lose that much life.)

Creatures you control have menace.

Whenever a creature you control perseveres, you draw a card and you lose 1 life. (A creature perseveres when it's dealt damage and doesn't die.)
{1}{B}: Deathmask Initiation deals 1 damage to target creature you control.

Deathwind Survivor's power and toughness are each equal to the number of enchantments you control.
Whenever an enchantment you control enters, put a +1/+1 counter on target creature.

Target creature gets -2/-2 until end of turn.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, return up to one target enchantment card from your graveyard to your hand.

When Debaser of Truth enters, if you control three or more Horrors, each opponent discards two cards.
Other Horror creatures you control get +1/+1.

Primal {B}{B} (During your turn, you may cast this spell for {B}{B} instead of playing a land.)
Search your library for a card and put that card into your hand, then shuffle. Exile Deceitful Tutor.

Target opponent discards a card. If a creature card was discarded this way, that player loses 3 life. If a land card was discarded this way, add {B}{B}. If a noncreature, nonland card was discarded this way, draw a card.

Menace (This creature can't be blocked except by two or more creatures.)

When Decrepit Hero dies, create a 2/2 black Soldier creature token.
Fleeting {1}{B} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

As an additional cost to cast Deepmire Abomination, reappropriate or pay {2}. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)
Menace

Destroy target creature or planeswalker.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

When Defiler of Farmsteads enters, each opponent loses 2 life and you gain 2 life.

As an additional cost to cast this spell, discard a nonland card.
Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Creatures with power greater than Deformed Vagrant's power can't block it.

Target creature gets +2/+0 and gains lifelink until end of turn.

When Delusive Shadows enters, each opponent loses life equal to the number of cards that player owns in exile.

Target player discards two cards.
Cycling {2}{B} ({2}{B}, Discard this card: Draw a card.)
When you cycle Dementia's Clutch, target player discards a card.

This spell costs {2} less to cast for each creature that died this turn.
Flying, trample

{1}{B}, Sacrifice another creature: Draw a card and 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.”)
{2}{B}, Sacrifice three Idols: Return Demon of Hubris from your graveyard to the battlefield. Activate only as a sorcery.

At the beginning of your end step, if you've sacrificed three or more permanents this turn, return Demon of Necessary Evil from your graveyard to the battlefield.

Create a 4/4 black Demon creature token with flying. You lose 3 life for each Demon you control.
Tether (Then if you cast this from your hand, you may exile it tethered to a creature you control. When it dies, you may cast this from exile without paying its mana cost.)

As an additional cost to cast this spell, pay 1 life.
Departed Evangel can't block.
You may cast Departed Evangel from your graveyard if a creature died this turn.

Menace
When Depraved Archknight enters, each opponent may pay 7 life. For each player that doesn't, you draw seven cards.