Hypnotic Specter

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

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.

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.

Lantern of Insight

Players play with the top card of their libraries revealed.
{T}, Sacrifice Lantern of Insight: Target player shuffles.

Telepathy

Your opponents play with their hands revealed.

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.