Coercion

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

Pit Imp

Flying
{B}: Pit Imp gets +1/+0 until end of turn. Activate no more than twice each turn.

Mindwarper

Mindwarper enters the battlefield with three +1/+1 counters on it.
{2}{B}, Remove a +1/+1 counter from Mindwarper: Target player discards a card. Activate only as a sorcery.

Swamp

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Dauthi Slayer

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

Foul Imp

Flying
When Foul Imp enters the battlefield, you lose 2 life.

Rabid Rats

{T}: Target blocking creature gets -1/-1 until end of turn.

Hornet Cannon

{3}, {T}: Create a 1/1 colorless Insect artifact creature token with flying and haste named Hornet. Destroy it at the beginning of the next end step.

Dark Banishing

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

Mind Peel

Buyback {2}{B}{B} (You may pay an additional {2}{B}{B} as you cast this spell. If you do, put this card into your hand as it resolves.)
Target player discards a card.

Death Stroke

Dauthi Mindripper

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Dauthi Mindripper attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Diabolic Edict

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.

Dauthi Horror

Shadow (This creature can block or be blocked by only creatures with shadow.)
Dauthi Horror can't be blocked by white creatures.

Dark Ritual

Portcullis

Whenever a creature enters the battlefield, if there are two or more other creatures on the battlefield, exile that creature. Return that card to the battlefield under its owner's control when Portcullis leaves the battlefield.