Scourge of the Undercity

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Scourge of the Undercity enters, another target creature you control gains lifelink until end of turn.

Ulcerate

Target creature gets -3/-3 until end of turn. You lose 3 life.

Infernal Grasp

Destroy target creature. You lose 2 life.

Audacious Thief

Whenever Audacious Thief attacks, you draw a card and you lose 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.)

Vampire Scrivener

Flying
Whenever you gain life during your turn, put a +1/+1 counter on Vampire Scrivener.
Whenever you lose life during your turn, put a +1/+1 counter on Vampire Scrivener.

Arrogant Outlaw

When Arrogant Outlaw enters, if an opponent lost life this turn, each opponent loses 2 life and you gain 2 life.

Metalspinner's Puzzleknot

When Metalspinner's Puzzleknot enters, you draw a card and you lose 1 life.
{2}{B}, Sacrifice Metalspinner's Puzzleknot: You draw a card and you lose 1 life.

Thriving Moor

Thriving Moor enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Howling Banshee

Flying
When Howling Banshee enters, each player loses 3 life.

Swamp

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.)

Alchemist's Gift

Target creature gets +1/+1 and gains your choice of deathtouch or lifelink until end of turn. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it. Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.