Repay in Kind

Each player's life total becomes the lowest life total among all players.

Have

Necropotence

Skip your draw step.
Whenever you discard a card, exile that card from your graveyard.
Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

The Sibsig Ceremony

Creature spells you cast cost {2} less to cast.
Whenever a creature you control enters, if you cast it, destroy that creature, then create a 2/2 black Zombie Druid creature token.

Greed's Gambit

When this enchantment enters, you draw three cards, gain 6 life, and create three 2/1 black Bat creature tokens with flying.
At the beginning of your end step, you discard a card, lose 2 life, and sacrifice a creature.
When this enchantment leaves the battlefield, you discard three cards, lose 6 life, and sacrifice three creatures.

Greven, Predator Captain

Menace
Greven gets +X/+0, where X is the amount of life you've lost this turn.
Whenever Greven attacks, you may sacrifice another creature. If you do, you draw cards equal to that creature's power and you lose life equal to that creature's toughness.

Phage the Untouchable

When Phage 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.

Auntie Blyte, Bad Influence

Flying
Whenever a source you control deals damage to you, put that many +1/+1 counters on Auntie Blyte.
{1}{R}, {T}, Remove X +1/+1 counters from Auntie Blyte: It deals X damage to any target.

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: This creature gets +1/+1 until end of turn.

Willowdusk, Essence Seer

{1}, {T}: Choose another target creature. Put a number of +1/+1 counters on it equal to the amount of life you gained this turn or the amount of life you lost this turn, whichever is greater. Activate only as a sorcery.

The Abyss

At the beginning of each player's upkeep, destroy target nonartifact creature that player controls of their choice. It can't be regenerated.

Rowan, Scion of War

Menace
{T}: Spells you cast this turn that are black and/or red cost {X} less to cast, where X is the amount of life you lost this turn. Activate only as a sorcery.

Sinkhole Surveyor

Flying
Whenever this creature attacks, you lose 1 life and this creature endures 1. (Put a +1/+1 counter on it or create a 1/1 white Spirit creature token.)

Pact Weapon

As long as this Equipment is attached to a creature, you don't lose the game for having 0 or less life.
Whenever equipped creature attacks, draw a card and reveal it. The creature gets +X/+X until end of turn and you lose X life, where X is that card's mana value.
Equip—Discard a card.

Will of the Abzan

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Any number of target opponents each sacrifice a creature with the greatest power among creatures that player controls and lose 3 life.
• Return target creature card from your graveyard to the battlefield.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Mortarion, Daemon Primarch

Flying
Primarch of the Death Guard — At the beginning of your end step, you may pay {X}. If you do, create X 2/2 black Astartes Warrior creature tokens with menace. X can't be greater than the amount of life you lost this turn.

Tsabo's Decree

Choose a creature type. Target player reveals their hand and discards all creature cards of that type. Then destroy all creatures of that type that player controls. They can't be regenerated.

Greed

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Leyline Prowler

Deathtouch, lifelink
{T}: Add one mana of any color.

Worthy Cost

As an additional cost to cast this spell, sacrifice a creature.
Exile target creature or planeswalker.

Bhaal, Lord of Murder

As long as your life total is less than or equal to half your starting life total, Bhaal has indestructible.
Whenever another nontoken creature you control dies, put a +1/+1 counter on target creature and goad it.

Praetor's Grasp

Search target opponent's library for a card and exile it face down. Then that player shuffles. You may play that card for as long as it remains exiled.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Village Rites

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

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Host of the Hereafter

This creature enters with two +1/+1 counters on it.
Whenever this creature or another creature you control dies, if it had counters on it, put its counters on up to one target creature you control.

Forsaken Miner

This creature can't block.
Whenever you commit a crime, you may pay {B}. If you do, return this card from your graveyard to the battlefield. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Torgaar, Famine Incarnate

As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed this way.
When Torgaar enters, up to one target player's life total becomes half their starting life total, rounded down.

Qarsi Revenant

Flying, deathtouch, lifelink
Renew — {2}{B}, Exile this card from your graveyard: Put a flying counter, a deathtouch counter, and a lifelink counter on target creature. Activate only as a sorcery.

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle this card, all creatures get -2/-2 until end of turn.

Murderous Betrayal

{B}{B}, Pay half your life, rounded up: Destroy target nonblack creature. It can't be regenerated.

Disrupt Decorum

Goad all creatures you don't control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)