Undercity Necrolisk

{1}, Sacrifice another creature: Put a +1/+1 counter on Undercity Necrolisk. It gains menace until end of turn. Activate only as a sorcery. (It can't be blocked except by two or more creatures.)

Barrage of Expendables

{R}, Sacrifice a creature: Barrage of Expendables deals 1 damage to any target.

Fume Spitter

Sacrifice Fume Spitter: Put a -1/-1 counter on target creature.

Altar's Reap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Pitchburn Devils

When Pitchburn Devils dies, it deals 3 damage to any target.

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.

Generator Servant

{T}, Sacrifice Generator Servant: Add {C}{C}. If that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and {T} as soon as it comes under your control.)

Tenacious Dead

When Tenacious Dead dies, you may pay {1}{B}. If you do, return it to the battlefield tapped under its owner's control.

Drainpipe Vermin

When Drainpipe Vermin dies, you may pay {B}. If you do, target player discards a card.

Altac Bloodseeker

Whenever a creature an opponent controls dies, Altac Bloodseeker gets +2/+0 and gains first strike and haste until end of turn. (It deals combat damage before creatures without first strike, and it can attack and {T} as soon as it comes under your control.)

Fanatical Firebrand

Haste
{T}, Sacrifice Fanatical Firebrand: It deals 1 damage to any target.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Macabre Mockery

Put target creature card from an opponent's graveyard onto the battlefield under your control. It gets +2/+0 and gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Tibalt, Rakish Instigator

Your opponents can't gain life.
−2: Create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."

Dead Revels

Spectacle {1}{B} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Return up to two target creature cards from your graveyard to your hand.

Gravepurge

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Tibalt's Rager

When Tibalt's Rager dies, it deals 1 damage to any target.
{1}{R}: Tibalt's Rager gets +2/+0 until end of turn.

Theater of Horrors

At the beginning of your upkeep, exile the top card of your library.
During your turn, if an opponent lost life this turn, you may play lands and cast spells from among cards exiled with Theater of Horrors.
{3}{R}: Theater of Horrors deals 1 damage to target opponent or planeswalker.

Herald of the Dreadhorde

When Herald of the Dreadhorde dies, amass Zombies 2. (Put two +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Spark Harvest

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Destroy target creature or planeswalker.

Bone Picker

This spell costs {3} less to cast if a creature died this turn.
Flying, deathtouch

Drill Bit

Spectacle {B} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Onyx Mage

{1}{B}: Target creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Lyzolda, the Blood Witch

{2}, Sacrifice a creature: Lyzolda, the Blood Witch deals 2 damage to any target if the sacrificed creature was red. Draw a card if the sacrificed creature was black.

Rakdos Guildgate

Rakdos Guildgate enters tapped.
{T}: Add {B} or {R}.

Costly Plunder

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Judith, the Scourge Diva

Other creatures you control get +1/+0.
Whenever a nontoken creature you control dies, Judith, the Scourge Diva deals 1 damage to any target.

Dreadbore

Disentomb

Return target creature card from your graveyard to your hand.

Swamp

Shock

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Gnawing Zombie

{1}{B}, Sacrifice a creature: Target player loses 1 life and you gain 1 life.

Mountain

Spinal Centipede

When Spinal Centipede dies, put a +1/+1 counter on target creature you control.

Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.

Vindictive Vampire

Whenever another creature you control dies, Vindictive Vampire deals 1 damage to each opponent and you gain 1 life.