Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Recoil

Return target permanent to its owner's hand. Then that player discards a card.

Telepathy

Your opponents play with their hands revealed.

Seer's Vision

Your opponents play with their hands revealed.
Sacrifice Seer's Vision: Look at target player's hand and choose a card from it. That player discards that card. Activate only as a sorcery.

Glasses of Urza

Cabal Interrogator

{X}{B}, {T}: Target player reveals X cards from their hand and you choose one of them. That player discards that card. Activate only as a sorcery.

Stromgald Spy

Whenever Stromgald Spy attacks and isn't blocked, you may have defending player play with their hand revealed for as long as Stromgald Spy remains on the battlefield. If you do, Stromgald Spy assigns no combat damage this turn.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Wandering Eye

Flying
Players play with their hands revealed.

Dimir Signet

Peek

Look at target player's hand.
Draw a card.

Spy Network

Look at target player's hand, the top card of that player's library, and any face-down creatures they control. Look at the top four cards of your library, then put them back in any order.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Nebuchadnezzar

{X}, {T}: Choose a card name. Target opponent reveals X cards at random from their hand. Then that player discards all cards with that name revealed this way. Activate only during your turn.

Zur's Weirding

Players play with their hands revealed.
If a player would draw a card, they reveal it instead. Then any other player may pay 2 life. If a player does, put that card into its owner's graveyard. Otherwise, that player draws a card.

Arcane Signet

Perplex

Counter target spell unless its controller discards their hand.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)