Go for the Throat

Heartless Summoning

Creature spells you cast cost {2} less to cast.
Creatures you control get -1/-1.

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Swamp

Gatekeeper of Malakir

Kicker {B} (You may pay an additional {B} as you cast this spell.)
When Gatekeeper of Malakir enters, if it was kicked, target player sacrifices a creature.

Wight of Precinct Six

Wight of Precinct Six gets +1/+1 for each creature card in your opponents' graveyards.

Grinding Station

{T}, Sacrifice an artifact: Target player mills three cards.
Whenever an artifact enters, you may untap Grinding Station.

Grasp of Darkness

Target creature gets -4/-4 until end of turn.

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.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.