Swamp

Knight of the Ebon Legion

{2}{B}: Knight of the Ebon Legion gets +3/+3 and gains deathtouch until end of turn.
At the beginning of your end step, if a player lost 4 or more life this turn, put a +1/+1 counter on Knight of the Ebon Legion. (Damage causes loss of life.)

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Devour in Shadow

Destroy target creature. It can't be regenerated. You lose life equal to that creature's toughness.

Infernal Grasp

Destroy target creature. You lose 2 life.

Death's Shadow

Death's Shadow gets -X/-X, where X is your life total.

Scourge of the Skyclaves

Kicker {4}{B}
When you cast this spell, if it was kicked, each player loses half their life, rounded up.
Scourge of the Skyclaves's power and toughness are each equal to 20 minus the highest life total among players.

Shadow of Mortality

If your life total is less than your starting life total, this spell costs {X} less to cast, where X is the difference.

Preacher of the Schism

Deathtouch
Whenever Preacher of the Schism attacks the player with the most life or tied for most life, create a 1/1 white Vampire creature token with lifelink.
Whenever Preacher of the Schism attacks while you have the most life or are tied for most life, you draw a card and you lose 1 life.

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Sign in Blood

Target player draws two cards and loses 2 life.

Dark Ritual

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Boggart Bog

As Boggart Bog enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Boggart Trawler

When Boggart Trawler enters, exile target player's graveyard.

Boggart Trawler // Boggart Bog

Vampire Lacerator

At the beginning of your upkeep, you lose 1 life unless an opponent has 10 or less life.