Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Davriel, Rogue Shadowmage

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, Davriel, Rogue Shadowmage deals 2 damage to them.
−1: Target player discards a card.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Necrogen Mists

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

Inquisition of Kozilek

Target player reveals their hand. You choose a nonland card from it with mana value 3 or less. That player discards that card.

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.

Urborg, Tomb of Yawgmoth

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

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature of their choice, then sacrifices a land of their choice.

Shrieking Affliction

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

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.

Swamp

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.)

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.