Tainted Sigil

{T}, Sacrifice this artifact: You gain life equal to the total life lost by all players this turn. (Damage causes loss of life.)

Kambal, Consul of Allocation

Whenever an opponent casts a noncreature spell, that player loses 2 life and you gain 2 life.

Soot Imp

Flying
Whenever a player casts a nonblack spell, that player loses 1 life.

Hushbringer

Flying, lifelink
Creatures entering or dying don't cause abilities to trigger.

Liability

Whenever a nontoken permanent is put into a player's graveyard from the battlefield, that player loses 1 life.

Kunoros, Hound of Athreos

Vigilance, menace, lifelink
Creature cards in graveyards can't enter the battlefield.
Players can't cast spells from graveyards.

Riot Control

You gain 1 life for each creature your opponents control. Prevent all damage that would be dealt to you this turn.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Blood Seeker

Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Linvala, Keeper of Silence

Flying
Activated abilities of creatures your opponents control can't be activated.

Liesa, Shroud of Dusk

Rather than pay {2} for each previous time you've cast this spell from the command zone this game, pay 2 life that many times.
Flying, lifelink
Whenever a player casts a spell, they lose 2 life.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.

Norn's Annex

({W/P} can be paid with either {W} or 2 life.)
Creatures can't attack you or planeswalkers you control unless their controller pays {W/P} for each of those creatures.

Simulacrum

You gain life equal to the damage dealt to you this turn. Simulacrum deals damage to target creature you control equal to the damage dealt to you this turn.

Doom Foretold

At the beginning of each player's upkeep, that player sacrifices a nonland, nontoken permanent of their choice. If that player can't, they discard a card, they lose 2 life, you draw a card, you gain 2 life, you create a 2/2 white Knight creature token with vigilance, then you sacrifice this enchantment.

False Cure

Until end of turn, whenever a player gains life, that player loses 2 life for each 1 life they gained.

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Rampage of the Valkyries

When this enchantment enters, create a 4/4 white Angel creature token with flying and vigilance.
Whenever an Angel you control dies, each other player sacrifices a creature of their choice.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if this enchantment has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Firja's Retribution

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 4/4 white Angel Warrior creature token with flying and vigilance.
II — Until end of turn, Angels you control gain "{T}: Destroy target creature with power less than this creature's power."
III — Angels you control gain double strike until end of turn.

Batwing Brume

Prevent all combat damage that would be dealt this turn if {W} was spent to cast this spell. Each player loses 1 life for each attacking creature they control if {B} was spent to cast this spell. (Do both if {W}{B} was spent.)

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Containment Priest

Flash
If a nontoken creature would enter and it wasn't cast, exile it instead.

Curse of Wizardry

As this enchantment enters, choose a color.
Whenever a player casts a spell of the chosen color, that player loses 1 life.

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. This artifact deals 1 damage to you.

Children of Korlis

Sacrifice this creature: You gain life equal to the life you've lost this turn. (Damage causes loss of life.)

Luminarch Ascension

At the beginning of each opponent's end step, if you didn't lose life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
{1}{W}: Create a 4/4 white Angel creature token with flying. Activate only if this enchantment has four or more quest counters on it.

Nightshade Harvester

Whenever a land an opponent controls enters, that player loses 1 life. Put a +1/+1 counter on this creature.

Isolation Cell

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