Dismal Backwater

Dismal Backwater enters tapped.
When Dismal Backwater enters, you gain 1 life.
{T}: Add {U} or {B}.

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Swamp

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Cast Down

Vraska's Fall

Each opponent sacrifices a creature or planeswalker and gets a poison counter.

Counterspell

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Bring the Ending

Counter target spell unless its controller pays {2}.
Corrupted — Counter that spell instead if its controller has three or more poison counters.

Blue Elemental Blast

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

Vivisurgeon's Insight

Draw three cards. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Serrated Arrows

Serrated Arrows enters with three arrowhead counters on it.
At the beginning of your upkeep, if there are no arrowhead counters on Serrated Arrows, sacrifice it.
{T}, Remove an arrowhead counter from Serrated Arrows: Put a -1/-1 counter on target creature.

Contentious Plan

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Island

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Grim Affliction

Put a -1/-1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Virulent Wound

Put a -1/-1 counter on target creature. When that creature dies this turn, its controller gets a poison counter.