Duress

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

Okiba-Gang Shinobi

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, that player discards two cards.

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Unburden

Target player discards two cards.
Cycling {2} ({2}, Discard this card: Draw a card.)

Beckon Apparition

Exile target card from a graveyard. Create a 1/1 white and black Spirit creature token with flying.

Phyrexian Rager

When this creature enters, you draw a card and you lose 1 life.

Sign in Blood

Target player draws two cards and loses 2 life.

Dauthi Slayer

Shadow (This creature can block or be blocked by only creatures with shadow.)
This creature attacks each combat if able.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Liliana's Specter

Flying
When this creature enters, each opponent discards a card.

Font of Return

{3}{B}, Sacrifice this enchantment: Return up to three target creature cards from your graveyard to your hand.

Befoul

Destroy target land or nonblack creature. It can't be regenerated.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Swamp

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)