Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Rule of Law

Each player can't cast more than one spell each turn.

Porphyry Nodes

At the beginning of your upkeep, destroy the creature with the least power. It can't be regenerated. If two or more creatures are tied for least power, you choose one of them.
When there are no creatures on the battlefield, sacrifice Porphyry Nodes.

Words of Waste

{1}: The next time you would draw a card this turn, each opponent discards a card instead.

Sphere of Safety

Creatures can't attack you or planeswalkers you control unless their controller pays {X} for each of those creatures, where X is the number of enchantments you control.

Descent into Madness

At the beginning of your upkeep, put a despair counter on Descent into Madness, then each player exiles X permanents they control and/or cards from their hand, where X is the number of despair counters on Descent into Madness.

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Desolation

At the beginning of each end step, each player who tapped a land for mana this turn sacrifices a land. Desolation deals 2 damage to each player who sacrificed a Plains this way.

Bottomless Pit

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

Lethal Vapors

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

Armageddon

Queen Marchesa

Deathtouch, haste
When Queen Marchesa enters the battlefield, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.

Hokori, Dust Drinker

Lands don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player untaps a land they control.

Oppression

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

Creeping Dread

At the beginning of your upkeep, each player discards a card. Each opponent who discarded a card that shares a card type with the card you discarded loses 3 life. (Players reveal the discarded cards simultaneously.)

Decree of Annihilation

Exile all artifacts, creatures, and lands from the battlefield, all cards from all graveyards, and all cards from all hands.
Cycling {5}{R}{R} ({5}{R}{R}, Discard this card: Draw a card.)
When you cycle Decree of Annihilation, destroy all lands.

Karmic Justice

Whenever a spell or ability an opponent controls destroys a noncreature permanent you control, you may destroy target permanent that opponent controls.