Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Terminate

Destroy target creature. It can't be regenerated.

Flying, haste
Whenever Blazing Specter deals combat damage to a player, that player discards a card.

Lightning Bolt deals 3 damage to any target.

When Flametongue Kavu enters the battlefield, it deals 4 damage to target creature.

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