Mana Leak

Counter target spell unless its controller pays {3}.

Spell Snare

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Jace Beleren

+2: Each player draws a card.
−1: Target player draws a card.
−10: Target player mills twenty cards.

Exhaustion

Creatures and lands target opponent controls don't untap during their next untap step.

Boomerang

Return target permanent to its owner's hand.

Isochron Scepter

Imprint — When Isochron Scepter enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Tectonic Edge

{T}: Add {C}.
{1}, {T}, Sacrifice Tectonic Edge: Destroy target nonbasic land. Activate only if an opponent controls four or more lands.

Tumble Magnet

Tumble Magnet enters with three charge counters on it.
{T}, Remove a charge counter from Tumble Magnet: Tap target artifact or creature.

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Ebony Owl Netsuke

At the beginning of each opponent's upkeep, if that player has seven or more cards in hand, Ebony Owl Netsuke deals 4 damage to that player.

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Serum Visions

Counterspell

Early Frost

Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Eye of Nowhere

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Guile

Guile can't be blocked except by three or more creatures.
If a spell or ability you control would counter a spell, instead exile that spell and you may play that card without paying its mana cost.
When Guile is put into a graveyard from anywhere, shuffle it into its owner's library.