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.

Marshland Bloodcaster

Flying
{1}{B}, {T}: Rather than pay the mana cost of the next spell you cast this turn, you may pay life equal to that spell's mana value.

Greed

Underworld Coinsmith

Constellation — Whenever Underworld Coinsmith or another enchantment enters the battlefield under your control, you gain 1 life.
{W}{B}, Pay 1 life: Each opponent loses 1 life.

Unspeakable Symbol

Pay 3 life: Put a +1/+1 counter on target creature.

Necrologia

Cast this spell only during your end step.
As an additional cost to cast this spell, pay X life.
Draw X cards.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Nightmare Lash

Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters the battlefield unattached and stays on the battlefield if the creature leaves.)

Minion of the Wastes

Trample
As Minion of the Wastes enters the battlefield, pay any amount of life.
Minion of the Wastes's power and toughness are each equal to the life paid as it entered the battlefield.

Razaketh, the Foulblooded

Flying, trample
Pay 2 life, Sacrifice another creature: Search your library for a card, put that card into your hand, then shuffle.

Withering Boon

As an additional cost to cast this spell, pay 3 life.
Counter target creature spell.

Selenia, Dark Angel

Flying
Pay 2 life: Return Selenia, Dark Angel to its owner's hand.

Revenge

Double your life total. Target opponent loses half their life, rounded up.

Revival

Return target creature card with mana value 3 or less from your graveyard to the battlefield.

Revival // Revenge

Bloodtracker

Flying
{B}, Pay 2 life: Put a +1/+1 counter on Bloodtracker.
When Bloodtracker leaves the battlefield, draw a card for each +1/+1 counter on it.

Phyrexian Unlife

You don't lose the game for having 0 or less life.
As long as you have 0 or less life, all damage is dealt to you as though its source had infect. (Damage is dealt to you in the form of poison counters.)

Final Payment

As an additional cost to cast this spell, pay 5 life or sacrifice a creature or enchantment.
Destroy target creature.

Adanto Vanguard

As long as Adanto Vanguard is attacking, it gets +2/+0.
Pay 4 life: Adanto Vanguard gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Collective Brutality

Escalate—Discard a card. (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Target opponent reveals their hand. You choose an instant or sorcery card from it. That player discards that card.
• Target creature gets -2/-2 until end of turn.
• Target opponent loses 2 life and you gain 2 life.

Repay in Kind

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

Vizkopa Guildmage

{1}{W}{B}: Target creature gains lifelink until end of turn.
{1}{W}{B}: Whenever you gain life this turn, each opponent loses that much life.

Vona, Butcher of Magan

Vigilance, lifelink
{T}, Pay 7 life: Destroy target nonland permanent. Activate only during your turn.

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Lich's Mastery

Hexproof
You can't lose the game.
Whenever you gain life, draw that many cards.
Whenever you lose life, for each 1 life you lost, exile a permanent you control or a card from your hand or graveyard.
When Lich's Mastery leaves the battlefield, you lose the game.

Promise of Power

Choose one —
• You draw five cards and you lose 5 life.
• Create an X/X black Demon creature token with flying, where X is the number of cards in your hand.
Entwine {4} (Choose both if you pay the entwine cost.)

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.)

Lich's Tomb

You don't lose the game for having 0 or less life.
Whenever you lose life, sacrifice a permanent for each 1 life you lost. (Damage causes loss of life.)

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Shadowcloak Vampire

Pay 2 life: Shadowcloak Vampire gains flying until end of turn. (It can't be blocked except by creatures with flying or reach.)

Lurking Evil

Pay half your life, rounded up: Lurking Evil becomes a 4/4 Phyrexian Horror creature with flying.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Lorcan, Warlock Collector

Flying
Whenever a creature card is put into an opponent's graveyard from anywhere, you may pay life equal to its mana value. If you do, put it onto the battlefield under your control. It's a Warlock in addition to its other types.
If a Warlock you control would die, exile it instead.

Lich's Mirror

If you would lose the game, instead shuffle your hand, your graveyard, and all permanents you own into your library, then draw seven cards and your life total becomes 20.

Souldrinker

Pay 3 life: Put a +1/+1 counter on Souldrinker.

Solemnity

Players can't get counters.
Counters can't be put on artifacts, creatures, enchantments, or lands.

Murderous Betrayal

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

Isolation Cell

Whenever an opponent casts a creature spell, that player loses 2 life unless they pay {2}.

Mischievous Poltergeist

Flying
Pay 1 life: Regenerate Mischievous Poltergeist.

Oketra's Last Mercy

Your life total becomes equal to your starting life total. Lands you control don't untap during your next untap step.

Moonlight Bargain

Look at the top five cards of your library. For each card, put that card into your graveyard unless you pay 2 life. Then put the rest into your hand.

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.

Temporal Extortion

When you cast this spell, any player may pay half their life, rounded up. If a player does, counter Temporal Extortion.
Take an extra turn after this one.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Hand of Vecna

At the beginning of combat on your turn, equipped creature or a creature you control named Vecna gets +X/+X until end of turn, where X is the number of cards in your hand.
Equip—Pay 1 life for each card in your hand.
Equip {2}

Plague of Vermin

Starting with you, each player may pay any amount of life. Repeat this process until no one pays life. Each player creates a 1/1 black Rat creature token for each 1 life they paid this way.

Lord of the Forsaken

Flying, trample
{B}, Sacrifice another creature: Target player mills three cards.
Pay 1 life: Add {C}. Spend this mana only to cast a spell from your graveyard.

Order of the Sacred Torch

{T}, Pay 1 life: Counter target black spell.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Bond of Agony

As an additional cost to cast this spell, pay X life.
Each other player loses X life.

Carrion Howler

Pay 1 life: Carrion Howler gets +2/-1 until end of turn.

Wall of Blood

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

Stromgald Cabal

{T}, Pay 1 life: Counter target white spell.

Ethereal Champion

Pay 1 life: Prevent the next 1 damage that would be dealt to Ethereal Champion this turn.