Gix's Caress

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Cast Down

Augur of Skulls

{1}{B}: Regenerate this creature.
Sacrifice this creature: Target player discards two cards. Activate only during your upkeep.

Mindstab

Target player discards three cards.
Suspend 4—{B} (Rather than cast this card from your hand, you may pay {B} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Distress

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

Sign in Blood

Target player draws two cards and loses 2 life.

Swamp

Duress

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

Mind Burst

Target player discards X cards, where X is one plus the number of cards named Mind Burst in all graveyards.

Undying Beast

When this creature dies, put it on top of its owner's library.

Tasigur's Cruelty

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

Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.