Anvil of Bogardan

Players have no maximum hand size.
At the beginning of each player's draw step, that player draws an additional card, then discards a card.

Dread of Night

Perish

Destroy all green creatures. They can't be regenerated.

Wasteland

{T}: Add {C}.
{T}, Sacrifice Wasteland: Destroy target nonbasic land.

Abyssal Specter

Flying
Whenever Abyssal Specter deals damage to a player, that player discards a card.

Stupor

Target opponent discards a card at random, then discards a card.

Ensnaring Bridge

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

Mind Warp

Look at target player's hand and choose X cards from it. That player discards those cards.

Infernal Tribute

{2}, Sacrifice a nontoken permanent: Draw a card.

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.

Gloom

White spells cost {3} more to cast.
Activated abilities of white enchantments cost {3} more to activate.

Bottomless Pit

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

Disrupting Scepter

{3}, {T}: Target player discards a card. Activate only during your turn.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Dark Ritual

Quicksand

{T}: Add {C}.
{T}, Sacrifice Quicksand: Target attacking creature without flying gets -1/-2 until end of turn.

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.

Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control of their choice, then sacrifices a third of the lands they control of their choice. Round up each time.

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.

Swamp

Nekrataal

First strike
When Nekrataal enters, destroy target nonartifact, nonblack creature. That creature can't be regenerated.

Diabolic Edict

Target player sacrifices a creature of their choice.

Drain Life

Spend only black mana on X.
Drain Life deals X damage to any target. You gain life equal to the damage dealt, but not more life than the player's life total before the damage was dealt, the planeswalker's loyalty before the damage was dealt, or the creature's toughness.