Exquisite Blood

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

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Kingpin's Pet

Flying
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Feat of Resistance

Put a +1/+1 counter on target creature you control. It gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)

Light of Promise

Enchant creature
Enchanted creature has "Whenever you gain life, put that many +1/+1 counters on this creature."

Immolating Glare

Underworld Coinsmith

Constellation — Whenever Underworld Coinsmith or another enchantment you control enters, you gain 1 life.
{W}{B}, Pay 1 life: Each opponent loses 1 life.

Luminous Bonds

Enchant creature
Enchanted creature can't attack or block.

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Plains

Lash of Thorns

Target creature gets +2/+1 and gains deathtouch until end of turn.

One Thousand Lashes

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.
At the beginning of the upkeep of enchanted creature's controller, that player loses 1 life.

Tithe Drinker

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Cleric of Life's Bond

Whenever another Cleric you control enters, you gain 1 life.
Whenever you gain life for the first time each turn, put a +1/+1 counter on Cleric of Life's Bond.

Swamp

Basilica Screecher

Sanguine Bond

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

Forsaken Sanctuary

Forsaken Sanctuary enters tapped.
{T}: Add {W} or {B}.

Mardu Hateblade

{B}: Mardu Hateblade gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

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.

Unnatural Endurance

Devoid (This card has no color.)
Target creature gets +2/+0 until end of turn. Regenerate it.

Restoration Gearsmith

When Restoration Gearsmith enters, return target artifact or creature card from your graveyard to your hand.

Agent of Masks

At the beginning of your upkeep, each opponent loses 1 life. You gain life equal to the life lost this way.

Orzhov Guildgate

This land enters tapped.
{T}: Add {W} or {B}.

Cliffhaven Vampire

Flying
Whenever you gain life, each opponent loses 1 life.

Pitiless Pontiff

{1}, Sacrifice another creature: Pitiless Pontiff gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)