Carnival of Souls

Whenever a creature enters, you lose 1 life and add {B}.

Priest of Gix

When Priest of Gix enters, add {B}{B}{B}.

Halo Hopper

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

Greedy Freebooter

When Greedy Freebooter dies, scry 1 and create a Treasure token. (To scry 1, look at the top card of your library. You may put that card on the bottom. A Treasure token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Shield Sphere

Defender
Whenever Shield Sphere blocks, put a -0/-1 counter on it.

Master of Dark Rites

{T}, Sacrifice another creature: Add {B}{B}{B}. Spend this mana only to cast Vampire, Cleric, and/or Demon spells.

Markov Baron

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Lifelink
Other Vampires you control get +1/+1.
Madness {2}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Ornithopter

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Memnite

Unmarked Grave

Search your library for a nonlegendary card, put that card into your graveyard, then shuffle.

Myr Moonvessel

Treacherous Pit-Dweller

When Treacherous Pit-Dweller enters from a graveyard, target opponent gains control of it.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Phyrexian Walker

Bridge from Below

Whenever a nontoken creature is put into your graveyard from the battlefield, if Bridge from Below is in your graveyard, create a 2/2 black Zombie creature token.
When a creature is put into an opponent's graveyard from the battlefield, if Bridge from Below is in your graveyard, exile Bridge from Below.