msem-instigator

Inversion of Flesh deals 5 damage to each creature and each planeswalker, and 5 damage to each player with the highest life total or tied for highest life total among players.

Whenever Infernal Barrier is dealt damage, it deals 1 damage to each opponent.

Until end of turn, target creature you control gains “{T}: This creature deals 1 damage to any target.”
Draw a card.

Reach
Whenever Elemental of Vengeance is dealt damage, it deals damage equal to its power to any target.

Whenever one or more cards are put into an opponent's graveyard from their hand or library, Cackling Tormentor deals 2 damage to any target.

Haste
At the beginning of your end step, sacrifice Breach Runner unless you return another creature you control to its owner's hand.

Creatures you control that have been dealt damage this turn get +2/+0.
When Bloodspawn enters, it deals 1 damage to target creature you control.

Bloodcrazed Acolyte enters with a +1/+1 counter on it for each player who lost life this turn.

At the beginning of each end step, if an opponent lost life this turn, you may put a +1/+1 counter on target creature.
Sacrifice a creature, Sacrifice Blood Cult Covenant: Blood Cult Covenant deals damage equal to the sacrificed creature's power to any target.

Whenever Ashen Host becomes the target of a spell, Ashen Host deals 2 damage to any target.

Target opponent chooses a number. When they do, choose one —
• That player discards their hand, then draws cards equal to the chosen number.
• Archivist's Torment deals damage to that player equal to the chosen number.

Choose two —
• Shuffle up to two target cards from graveyards into their owners' libraries.
• Create a 1/1 black Skeleton creature token. You lose 1 life.
• Sacrifice a permanent. Draw a card.

{2}{B}, Sacrifice a Clue: Target creature gets -3/-3 until end of turn.

When Writhing Gateway enters, you may discard a card. If you do, create a 5/3 black Horror creature token.
{1}{B}{B}, Discard a card: Create a 5/3 black Horror creature token.

Target creature gets -6/-6 until end of turn.
Create a black enchantment token named Blight with “At the beginning of your upkeep, you lose 1 life.”

Target creature gets -1/-1 until end of turn.
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Flashback—{B}, Pay 2 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

As an additional cost to cast this spell, discard a card or pay {4}.
Destroy target creature.

Deathtouch
{U/B}: Change a target of target spell or ability that targets Serafina to another creature you control.
Whenever Serafina deals damage to a player, at the beginning of the next end step, that player loses life equal to the life they lost this turn.

When Sadistic Indulgence enters, create three 1/1 white Human creature tokens with “This creature can't attack or block.”
Pay 1 life: Destroy target nonland permanent you control.

At the beginning of your upkeep, you lose 1 life, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Whenever you sacrifice a permanent, each opponent loses 1 life.

{T}: Target player loses 1 life.
Whenever you cast a spell from your graveyard, untap Paincaller.

Play with the top card of your library revealed.
Whenever you draw a card, destroy each creature with the same mana value as that card.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{3}: Unlock Mortal's Conundrum. If the revealed card is black, put it into your hand. Otherwise, put it on top of your library.
At the beginning of your upkeep, if Mortal's Conundrum is unlocked, you lose 2 life.

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