Howl from Beyond

Target creature gets +X/+0 until end of turn.

Dark Ritual

Mind Twist

Target player discards X cards at random.

Mindstab Thrull

Whenever Mindstab Thrull attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Sengir Vampire

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by Sengir Vampire this turn dies, put a +1/+1 counter on Sengir Vampire.

Sol Ring

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Black Knight

First strike (This creature deals combat damage before creatures without first strike.)
Protection from white (This creature can't be blocked, targeted, dealt damage, or enchanted by anything white.)

Bad Moon

Hymn to Tourach

Target player discards two cards at random.

Order of the Ebon Hand

Protection from white
{B}: Order of the Ebon Hand gains first strike until end of turn.
{B}{B}: Order of the Ebon Hand gets +1/+0 until end of turn.

Demonic Tutor

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

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

The Rack

As The Rack enters, choose an opponent.
At the beginning of the chosen player's upkeep, The Rack deals X damage to that player, where X is 3 minus the number of cards in their hand.