Price of Knowledge

Players have no maximum hand size.
At the beginning of each opponent's upkeep, Price of Knowledge deals damage to that player equal to the number of cards in that player's hand.

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.

Misers' Cage

At the beginning of each opponent's upkeep, if that player has five or more cards in hand, Misers' Cage deals 2 damage to that player.

Captive Audience

Captive Audience enters under the control of an opponent of your choice.
At the beginning of your upkeep, choose one that hasn't been chosen —
• Your life total becomes 4.
• Discard your hand.
• Each opponent creates five 2/2 black Zombie creature tokens.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Ebony Owl Netsuke

At the beginning of each opponent's upkeep, if that player has seven or more cards in hand, Ebony Owl Netsuke deals 4 damage to that player.

Head Games

Target opponent puts the cards from their hand on top of their library. Search that player's library for that many cards. The player puts those cards into their hand, then shuffles.

Wheel of Misfortune

Each player secretly chooses a number 0 or greater, then all players reveal those numbers simultaneously and determine the highest and lowest numbers revealed this way. Wheel of Misfortune deals damage equal to the highest number to each player who chose that number. Each player who didn't choose the lowest number discards their hand, then draws seven cards.

Lethal Vapors

Whenever a creature enters, destroy it.
{0}: Destroy Lethal Vapors. You skip your next turn. Any player may activate this ability.

Do or Die

Separate all creatures target player controls into two piles. Destroy all creatures in the pile of that player's choice. They can't be regenerated.

Warlock Class

(Gain the next level as a sorcery to add its ability.)
At the beginning of your end step, if a creature died this turn, each opponent loses 1 life.
{1}{B}: Level 2
When this Class becomes level 2, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
{6}{B}: Level 3
At the beginning of your end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Umbilicus

At the beginning of each player's upkeep, that player may pay 2 life. If they don't, they return a permanent they control to its owner's hand.

Thumbscrews

At the beginning of your upkeep, if you have five or more cards in hand, Thumbscrews deals 1 damage to target opponent or planeswalker.

Tyrant's Choice

Will of the council — Starting with you, each player votes for death or torture. If death gets more votes, each opponent sacrifices a creature of their choice. If torture gets more votes or the vote is tied, each opponent loses 4 life.

Skullcage

At the beginning of each opponent's upkeep, Skullcage deals 2 damage to that player unless they have exactly three or exactly four cards in hand.

Mask of Intolerance

At the beginning of each player's upkeep, if there are four or more basic land types among lands that player controls, Mask of Intolerance deals 3 damage to that player.

Psychogenic Probe

Whenever a spell or ability causes a player to shuffle their library, Psychogenic Probe deals 2 damage to that player.

Dingus Staff

Whenever a creature dies, Dingus Staff deals 2 damage to that creature's controller.

Tangle Wire

Fading 4 (This artifact enters with four fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
At the beginning of each player's upkeep, that player taps an untapped artifact, creature, or land they control for each fade counter on Tangle Wire.

Deadlock Trap

Deadlock Trap enters tapped.
When Deadlock Trap enters, you get {E}{E} (two energy counters).
{T}, Pay {E}: Tap target creature or planeswalker. Its activated abilities can't be activated this turn.

Oubliette

When Oubliette enters, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Swamp

Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Cursed Rack

As Cursed Rack enters, choose an opponent.
The chosen player's maximum hand size is four.

Bond of Agony

As an additional cost to cast this spell, pay X life.
Each other player loses X life.

Pyxis of Pandemonium

{T}: Each player exiles the top card of their library face down.
{7}, {T}, Sacrifice Pyxis of Pandemonium: Each player turns face up all cards they own exiled with Pyxis of Pandemonium, then puts all permanent cards among them onto the battlefield.

Paupers' Cage

At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, Paupers' Cage deals 2 damage to that player.

Goblin Game

Each player hides at least one item, then all players reveal them simultaneously. Each player loses life equal to the number of items they revealed. The player who revealed the fewest items then loses half their life, rounded up. If two or more players are tied for fewest, each loses half their life, rounded up.

Portcullis

Whenever a creature enters, if there are two or more other creatures on the battlefield, exile that creature. Return that card to the battlefield under its owner's control when Portcullis leaves the battlefield.

Wheel of Torture

At the beginning of each opponent's upkeep, Wheel of Torture deals X damage to that player, where X is 3 minus the number of cards in their hand.

Scalding Tongs

At the beginning of your upkeep, if you have three or fewer cards in hand, Scalding Tongs deals 1 damage to target opponent or planeswalker.

Booby Trap

As Booby Trap enters, choose an opponent and a card name other than a basic land card name.
The chosen player reveals each card they draw.
When the chosen player draws a card with the chosen name, sacrifice Booby Trap. If you do, Booby Trap deals 10 damage to that player.

Skeleton Shard

{3}, {T} or {B}, {T}: Return target artifact creature card from your graveyard to your hand.

Iron Maiden

At the beginning of each opponent's upkeep, Iron Maiden deals X damage to that player, where X is the number of cards in their hand minus 4.

Isolation Cell

Whenever an opponent casts a creature spell, that player loses 2 life unless they pay {2}.

Black Vise

As Black Vise enters, choose an opponent.
At the beginning of the chosen player's upkeep, Black Vise deals X damage to that player, where X is the number of cards in their hand minus 4.

Razor Pendulum

At the beginning of each player's end step, if that player has 5 or less life, Razor Pendulum deals 2 damage to that player.

Lich's Mastery

Hexproof
You can't lose the game.
Whenever you gain life, draw that many cards.
Whenever you lose life, for each 1 life you lost, exile a permanent you control or a card from your hand or graveyard.
When Lich's Mastery leaves the battlefield, you lose the game.

Viseling

At the beginning of each opponent's upkeep, Viseling deals X damage to that player, where X is the number of cards in their hand minus 4.