Diabolic Tutor

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

Sudden Death

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Target creature gets -4/-4 until end of turn.

Essence Harvest

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

Swamp

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Exsanguinate

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

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Death Wind

Target creature gets -X/-X until end of turn.

Mind Rot

Barter in Blood

Each player sacrifices two creatures of their choice.

Go for the Throat

Beseech the Queen

({2/B} can be paid with any two mana or with {B}. This card's mana value is 6.)
Search your library for a card with mana value less than or equal to the number of lands you control, reveal it, put it into your hand, then shuffle.

Doom Blade

Ashenmoor Cohort

This creature gets +1/+1 as long as you control another black creature.

Bala Ged Scorpion

When this creature enters, you may destroy target creature with power 1 or less.

Fear

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)

Aphotic Wisps

Target creature becomes black and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
Draw a card.

Armor Thrull

{T}, Sacrifice this creature: Put a +1/+2 counter on target creature.

Exile into Darkness

Target player sacrifices a creature of their choice with mana value 3 or less.
At the beginning of your upkeep, if you have more cards in hand than each opponent, you may return this card from your graveyard to your hand.