Cloak of Confusion

Enchant creature you control
Whenever enchanted creature attacks and isn't blocked, you may have it assign no combat damage this turn. If you do, defending player discards a card at random.

Gwendlyn Di Corci

{T}: Target player discards a card at random. Activate only during your turn.

Mind Twist

Target player discards X cards at random.

Fall

Target player reveals two cards at random from their hand, then discards each nonland card revealed this way.

Rise

Return target creature card from a graveyard and target creature on the battlefield to their owners' hands.

Rise // Fall

Rag Man

{B}{B}{B}, {T}: Target opponent reveals their hand and discards a creature card at random. Activate only during your turn.

Bottomless Pit

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

Hive Mind

Whenever a player casts an instant or sorcery spell, each other player copies that spell. Each of those players may choose new targets for their copy.

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Crabomination

Emerge from artifact {5}{B}{B} (You may cast this spell by sacrificing an artifact and paying the emerge cost reduced by that artifact's mana value.)
When this creature enters, target opponent exiles the top card of their library, a card at random from their graveyard, and a card at random from their hand. You may cast a spell from among cards exiled this way without paying its mana cost.

Mind Knives

Target opponent discards a card at random.

Past in Flames

Each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Exalted Flamer of Tzeentch

Sorcerous Inspiration — At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Fire of Tzeentch — Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent.

Corrupt Official

{2}{B}: Regenerate this creature.
Whenever this creature becomes blocked, defending player discards a card at random.

Chef's Kiss

Gain control of target spell that targets only a single permanent or player. Copy it, then reselect the targets at random for the spell and the copy. The new targets can't be you or a permanent you control.

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Last One Standing

Choose a creature at random, then destroy the rest.

Skull Rend

Skull Rend deals 2 damage to each opponent. Those players each discard two cards at random.

Mindwhip Sliver

All Slivers have "{2}, Sacrifice this permanent: Target player discards a card at random. Activate only as a sorcery."

Hypnotic Specter

Flying
Whenever this creature deals damage to an opponent, that player discards a card at random.

Kefka, Dancing Mad

During your turn, Kefka has indestructible.
At the beginning of your end step, exile a card at random from each opponent's graveyard. You may cast any number of spells from among cards exiled this way without paying their mana costs. Then each player who owns a spell you cast this way loses life equal to its mana value.

Skullknocker Ogre

Whenever this creature deals damage to an opponent, that player discards a card at random. If the player does, they draw a card.

Tourach, Dread Cantor

Kicker {B}{B} (You may pay an additional {B}{B} as you cast this spell.)
Protection from white
Whenever an opponent discards a card, put a +1/+1 counter on Tourach.
When Tourach enters, if it was kicked, target opponent discards two cards at random.

Rakdos Ringleader

First strike
Whenever this creature deals combat damage to a player, that player discards a card at random.
{B}: Regenerate this creature.

Alpharael, Stonechosen

Ward—Discard a card at random.
Void — Whenever Alpharael attacks, if a nonland permanent left the battlefield this turn or a spell was warped this turn, defending player loses half their life, rounded up.

Black Cat

When this creature dies, target opponent discards a card at random.

Mind Shatter

Resounding Scream

Target player discards a card at random.
Cycling {5}{U}{B}{R} ({5}{U}{B}{R}, Discard this card: Draw a card.)
When you cycle this card, target player discards two cards at random.

River Song's Diary

Imprint — Whenever a player casts an instant or sorcery spell from their hand, exile it instead of putting it into a graveyard as it resolves.
At the beginning of your upkeep, if there are four or more cards exiled with this artifact, choose one of them at random. You may cast it without paying its mana cost.

Elkin Lair

At the beginning of each player's upkeep, that player exiles a card at random from their hand. The player may play that card this turn. At the beginning of the next end step, if the player hasn't played the card, they put it into their graveyard.

Balor

Flying
Whenever this creature attacks or dies, choose one or more. Each mode must target a different player.
• Target opponent draws three cards, then discards three cards at random.
• Target opponent sacrifices a nontoken artifact of their choice.
• This creature deals damage to target opponent equal to the number of cards in their hand.

Hymn to Tourach

Target player discards two cards at random.

Skullscorch

Target player discards two cards at random unless that player has Skullscorch deal 4 damage to them.

Dementia Sliver

All Slivers have "{T}: Choose a card name. Target opponent reveals a card at random from their hand. If that card has the chosen name, that player discards it. Activate only during your turn."

Rona, Tolarian Obliterator

Trample
Whenever a source deals damage to Rona, that source's controller exiles a card from their hand at random. If it's a land card, you may put it onto the battlefield under your control. Otherwise, you may cast it without paying its mana cost.

Rona, Herald of Invasion

Whenever you cast a legendary spell, untap Rona.
{T}: Draw a card, then discard a card.
{5}{B/P}: Transform Rona. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.)

Rona, Herald of Invasion // Rona, Tolarian Obliterator

Sanity Gnawers

When this creature enters, target player discards a card at random.

Noggle Ransacker

When this creature enters, each player draws two cards, then discards a card at random.

Skyship Weatherlight

When Skyship Weatherlight enters, search your library for any number of artifact and/or creature cards, exile them, then shuffle.
{4}, {T}: Choose a card at random that was exiled with Skyship Weatherlight. Put that card into its owner's hand.