Endless Whispers

Each creature has "When this creature dies, choose target opponent. That player puts this card from its owner's graveyard onto the battlefield under their control at the beginning of the next end step."

Banehound

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Diabolic Edict

Target player sacrifices a creature of their choice.

Chariot of Victory

Equipped creature has first strike, trample, and haste.
Equip {1}

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Swamp

Royal Assassin

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Wall of Souls

Defender (This creature can't attack.)
Whenever Wall of Souls is dealt combat damage, it deals that much damage to target opponent or planeswalker.

Phage the Untouchable

When Phage the Untouchable enters, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

Dark Ritual

Grafted Wargear

Equipped creature gets +3/+2.
Whenever Grafted Wargear becomes unattached from a permanent, sacrifice that permanent.
Equip {0} ({0}: Attach to target creature you control. Equip only as a sorcery.)

Dreadmalkin

Menace (This creature can't be blocked except by two or more creatures.)
{2}{B}, Sacrifice another creature or planeswalker: Put two +1/+1 counters on Dreadmalkin.