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.

Swamp

Gatekeeper of Malakir

Kicker {B} (You may pay an additional {B} as you cast this spell.)
When Gatekeeper of Malakir enters the battlefield, 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.

Grasp of Darkness

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

Heartless Summoning

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

Dark Ritual

Altar of the Brood

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Go for the Throat

Myr Retriever

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

Grinding Station

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

Dimir Machinations

Look at the top three cards of target player's library. Exile any number of those cards, then put the rest back in any order.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)