Foul Familiar

Foul Familiar can't block.
{B}, Pay 1 life: Return Foul Familiar to its owner's hand.

Sanitarium Skeleton

{2}{B}: Return Sanitarium Skeleton from your graveyard to your hand.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Death Denied

Return X target creature cards from your graveyard to your hand.

Dark Ritual

Swamp

Epicure of Blood

Whenever you gain life, each opponent loses 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.)

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Cadaver Imp

Flying
When Cadaver Imp enters, you may return target creature card from your graveyard to your hand.

Syndicate Enforcer

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.)

Sleeper's Guile

Enchant creature
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When Sleeper's Guile is put into a graveyard from the battlefield, return Sleeper's Guile to its owner's hand.