Liliana's Caress

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

Megrim

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

The Rack

As The Rack enters, choose an opponent.
At the beginning of the chosen player's upkeep, The Rack deals X damage to that player, where X is 3 minus the number of cards in their hand.

Liliana of the Veil

+1: Each player discards a card.
−2: Target player sacrifices a creature.
−6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.

Necrogen Mists

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

Damnation

Destroy all creatures. They can't be regenerated.

Mind Rot

Hymn to Tourach

Target player discards two cards at random.

Oppression

Whenever a player casts a spell, that player discards a card.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Liliana's Specter

Flying
When Liliana's Specter enters, each opponent discards a card.

Shrieking Affliction

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 3 life.

Mindslicer

When Mindslicer dies, each player discards their hand.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Blightning

Blightning deals 3 damage to target player or planeswalker. That player or that planeswalker's controller discards two cards.