Engineered Plague

As Engineered Plague enters, choose a creature type.
All creatures of the chosen type get -1/-1.

Mana Leak

Counter target spell unless its controller pays {3}.

Boomerang

Return target permanent to its owner's hand.

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Counterspell

Swamp

Stifle

Counter target activated or triggered ability. (Mana abilities can't be targeted.)

Duress

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

Smother

Destroy target creature with mana value 3 or less. It can't be regenerated.

Accumulated Knowledge

Draw a card, then draw cards equal to the number of cards named Accumulated Knowledge in all graveyards.

Diabolic Edict

Infest

All creatures get -2/-2 until end of turn.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Island

Parallax Tide

Fading 5 (This enchantment enters with five fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
Remove a fade counter from Parallax Tide: Exile target land.
When Parallax Tide leaves the battlefield, each player returns to the battlefield all cards they own exiled with Parallax Tide.

Black Vise

As Black Vise enters, choose an opponent.
At the beginning of the chosen player's upkeep, Black Vise deals X damage to that player, where X is the number of cards in their hand minus 4.

Chill

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Annul

Counter target artifact or enchantment spell.

Chain of Vapor

Return target nonland permanent to its owner's hand. Then that permanent's controller may sacrifice a land. If the player does, they may copy this spell and may choose a new target for that copy.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.