Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Elas il-Kor, Sadistic Pilgrim

Deathtouch
Whenever another creature you control enters, you gain 1 life.
Whenever another creature you control dies, each opponent loses 1 life.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Astarion, the Decadent

Deathtouch, lifelink
At the beginning of your end step, choose one —
• Feed — Target opponent loses life equal to the amount of life they lost this turn.
• Friends — You gain life equal to the amount of life you gained this turn.

Debt to the Deathless

Each opponent loses two times X life. You gain life equal to the life lost this way.

Chalice of Death

Chalice of Life

{T}: You gain 1 life. Then if you have at least 10 life more than your starting life total, transform Chalice of Life.

Chalice of Life // Chalice of Death

Sign in Blood

Target player draws two cards and loses 2 life.

Shambling Vent

Shambling Vent enters tapped.
{T}: Add {W} or {B}.
{1}{W}{B}: Shambling Vent becomes a 2/3 white and black Elemental creature with lifelink until end of turn. It's still a land.

Consume

Target player sacrifices a creature with the greatest power among creatures they control. You gain life equal to its power.

Consecrate

Exile target card from a graveyard.
Draw a card.

Consecrate // Consume

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on this creature.

Obzedat, Ghost Council

When Obzedat, Ghost Council enters, target opponent loses 2 life and you gain 2 life.
At the beginning of your end step, you may exile Obzedat. If you do, return it to the battlefield under its owner's control at the beginning of your next upkeep. It gains haste.

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

Tablet of the Guilds

As Tablet of the Guilds enters, choose two colors.
Whenever you cast a spell, if it's at least one of the chosen colors, you gain 1 life for each of the chosen colors it is.

Soul Warden

Whenever another creature enters, you gain 1 life.

Scoured Barrens

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {B}.

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.

Gloom Sower

Whenever Gloom Sower becomes blocked by a creature, that creature's controller loses 2 life and you gain 2 life.

Drana's Emissary

Flying
At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Serra Faithkeeper

Invasion of Dominaria

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Dominaria enters, you gain 4 life and draw a card.

Invasion of Dominaria // Serra Faithkeeper

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.)

Ajani's Mantra

At the beginning of your upkeep, you may gain 1 life.

Mortify

Markov Purifier

Lifelink
At the beginning of your end step, if you gained life this turn, you may pay {2}. If you do, draw 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.

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Cleric Class

(Gain the next level as a sorcery to add its ability.)
If you would gain life, you gain that much life plus 1 instead.
{3}{W}: Level 2
Whenever you gain life, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target creature card from your graveyard to the battlefield. You gain life equal to that creature's toughness.

Pulse of the Fields

You gain 4 life. Then if an opponent has more life than you, return Pulse of the Fields to its owner's hand.