Sign in Blood

Target player draws two cards and loses 2 life.

Pontiff of Blight

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.)
Other creatures you control have extort. (If a creature has multiple instances of extort, each triggers separately.)

Blood Tithe

Each opponent loses 3 life. You gain life equal to the life lost this way.

Essence Harvest

Target player loses X life and you gain X life, where X is the greatest power among creatures you control.

Banehound

Swamp

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.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Demon's Horn

Whenever a player casts a black spell, you may gain 1 life.

Basilica Screecher

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.)