Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Eye of Vecna

When Eye of Vecna enters, you draw a card and you lose 2 life.
At the beginning of your upkeep, you may pay {2}. If you do, you draw a card and you lose 2 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.

Scoured Barrens

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

Gixian Puppeteer

Whenever you draw your second card each turn, each opponent loses 2 life and you gain 2 life.
When Gixian Puppeteer dies, return another target creature card with mana value 3 or less from your graveyard to the battlefield.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Kambal, Consul of Allocation

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

Vindicate

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.

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.

Profane Memento

Whenever a creature card is put into an opponent's graveyard from anywhere, you gain 1 life.

Cut Down

Destroy target creature with total power and toughness 5 or less.

Plains

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Souls of the Faultless

Defender (This creature can't attack.)
Whenever Souls of the Faultless is dealt combat damage, you gain that much life and attacking player loses that much life.

Demogorgon's Clutches

Target opponent discards two cards, mills two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)