Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Smother

Destroy target creature with mana value 3 or less. It can't be regenerated.

Black Cat

When Black Cat dies, target opponent discards a card at random.

Duress

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

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, draw a card.

Sudden Edict

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 player sacrifices a creature of their choice.

Mind Rot

Raven's Crime

Target player discards a card.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Blackmail

Target player reveals three cards from their hand and you choose one of them. That player discards that card.

Night's Whisper

Swamp

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.