Recoil

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

Megrim

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

Eye of Nowhere

Return target permanent to its owner's hand.

Seal of Removal

Sacrifice this enchantment: Return target creature to its owner's hand.

Island

Boomerang

Rackling

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is 3 minus the number of cards in their hand.

Geth's Grimoire

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

Cowardice

Whenever a creature becomes the target of a spell or ability, return that creature to its owner's hand. (It won't be affected by the spell or ability.)

Swamp

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.)

Icy Manipulator

{1}, {T}: Tap target artifact, creature, or land.

Warped Devotion

Whenever a permanent is returned to a player's hand, that player discards a card.

Sway of Illusion

Any number of target creatures become the color of your choice until end of turn.
Draw a card.