Cast Down

Demon of Catastrophes

As an additional cost to cast this spell, sacrifice a creature.
Flying, trample

Knight of Malice

First strike
Hexproof from white (This creature can't be the target of white spells or abilities your opponents control.)
Knight of Malice gets +1/+0 as long as any player controls a white permanent.

Graveyard Marshal

{2}{B}, Exile a creature card from your graveyard: Create a tapped 2/2 black Zombie creature token.

Murder

Vona's Hunger

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Each opponent sacrifices a creature. If you have the city's blessing, instead each opponent sacrifices half the creatures they control, rounded up.

Dire Fleet Poisoner

Flash
Deathtouch
When Dire Fleet Poisoner enters, target attacking Pirate you control gets +1/+1 and gains deathtouch until end of turn.

Spawn of Mayhem

Spectacle {1}{B}{B} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Flying, trample
At the beginning of your upkeep, Spawn of Mayhem deals 1 damage to each player. Then if you have 10 or less life, put a +1/+1 counter on Spawn of Mayhem.

Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

Doom Whisperer

Flying, trample
Pay 2 life: Surveil 2. (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.)