Pandemonium

Whenever a creature enters, that creature's controller may have it deal damage equal to its power to any target of their choice.

Time Reversal

Each player shuffles their hand and graveyard into their library, then draws seven cards. Exile Time Reversal.

Mass Hysteria

Dream Halls

Rather than pay the mana cost for a spell, its controller may discard a card that shares a color with that spell.

Show and Tell

Each player may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.

Scrambleverse

For each nonland permanent, choose a player at random. Then each player gains control of each permanent for which they were chosen. Untap those permanents.

Grip of Chaos

Whenever a spell or ability is put onto the stack, if it has a single target, reselect its target at random. (Select from among all legal targets.)

Spiteful Visions

At the beginning of each player's draw step, that player draws an additional card.
Whenever a player draws a card, this enchantment deals 1 damage to that player.

Ricochet

Whenever a player casts a spell that targets a single player, each player rolls a six-sided die. Change the target of that spell to the player with the lowest result. Reroll to break ties, if necessary.

Possibility Storm

Whenever a player casts a spell from their hand, that player exiles it, then exiles cards from the top of their library until they exile a card that shares a card type with it. That player may cast that card without paying its mana cost. Then they put all cards exiled with this enchantment on the bottom of their library in a random order.

Confusion in the Ranks

Whenever an artifact, creature, or enchantment enters, its controller chooses target permanent another player controls that shares a card type with it. Exchange control of those permanents.

Null Rod

Activated abilities of artifacts can't be activated.

Concordant Crossroads

Vision Skeins

Bubble Matrix

Prevent all damage that would be dealt to creatures.

Meekstone

Creatures with power 3 or greater don't untap during their controllers' untap steps.

The Great Aurora

Each player shuffles all cards from their hand and all permanents they own into their library, then draws that many cards. Each player may put any number of land cards from their hand onto the battlefield. Exile The Great Aurora.

Worldfire

Exile all permanents. Exile all cards from all hands and graveyards. Each player's life total becomes 1.

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.

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Static Orb

As long as this artifact is untapped, players can't untap more than two permanents during their untap steps.

Rites of Flourishing

At the beginning of each player's draw step, that player draws an additional card.
Each player may play an additional land on each of their turns.

Hand to Hand

During combat, players can't cast instant spells or activate abilities that aren't mana abilities.

Lifeline

Whenever a creature dies, if another creature is on the battlefield, return the first card to the battlefield under its owner's control at the beginning of the next end step.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Eureka

Starting with you, each player may put a permanent card from their hand onto the battlefield. Repeat this process until no one puts a card onto the battlefield.

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Repercussion

Whenever a creature is dealt damage, this enchantment deals that much damage to that creature's controller.

Necrotic Plague

Enchant creature
Enchanted creature has "At the beginning of your upkeep, sacrifice this creature."
When enchanted creature dies, its controller chooses target creature one of their opponents controls. Return this card from its owner's graveyard to the battlefield attached to that creature.

Humility

All creatures lose all abilities and have base power and toughness 1/1.

Font of Mythos

At the beginning of each player's draw step, that player draws two additional cards.

Repay in Kind

Each player's life total becomes the lowest life total among all players.

Omen Machine

Players can't draw cards.
At the beginning of each player's draw step, that player exiles the top card of their library. If it's a land card, the player puts it onto the battlefield. Otherwise, the player casts it without paying its mana cost if able.

Balance

Each player chooses a number of lands they control equal to the number of lands controlled by the player who controls the fewest, then sacrifices the rest. Players discard cards and sacrifice creatures the same way.

Infernal Genesis

At the beginning of each player's upkeep, that player mills a card. Then they create X 1/1 black Minion creature tokens, where X is the milled card's mana value.

Thieves' Auction

Exile all nontoken permanents. Starting with you, each player chooses one of the exiled cards and puts it onto the battlefield tapped under their control. Repeat this process until all cards exiled this way have been chosen.

Oath of Ghouls

At the beginning of each player's upkeep, that player chooses target player whose graveyard has fewer creature cards in it than their graveyard does and is their opponent. The first player may return a creature card from their graveyard to their hand.

Dictate of Kruphix

Flash (You may cast this spell any time you could cast an instant.)
At the beginning of each player's draw step, that player draws an additional card.

Dual Nature

Whenever a nontoken creature enters, its controller creates a token that's a copy of that creature.
Whenever a nontoken creature leaves the battlefield, exile all tokens with the same name as that creature.
When this enchantment leaves the battlefield, exile all tokens created with this enchantment.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Wild Evocation

At the beginning of each player's upkeep, that player reveals a card at random from their hand. If it's a land card, the player puts it onto the battlefield. Otherwise, the player casts it without paying its mana cost if able.

Fraying Omnipotence

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