Scheming Aspirant

Whenever you proliferate, each opponent loses 2 life and you gain 2 life.

The Fair Basilica

The Fair Basilica enters tapped.
{T}: Add {W}.
{1}{W}, {T}, Sacrifice The Fair Basilica: Draw a card.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

The Seedcore

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast Phyrexian creature spells.
Corrupted — {T}: Target 1/1 creature gets +2/+1 until end of turn. Activate only if an opponent has three or more poison counters.

Compleat Devotion

Target creature you control gets +2/+2 until end of turn. If that creature has toxic, draw a card.

Plains

Crawling Chorus

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Crawling Chorus dies, create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block."

Infectious Inquiry

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

Basilica Skullbomb

{1}, Sacrifice Basilica Skullbomb: Draw a card.
{2}{W}, Sacrifice Basilica Skullbomb: Target creature you control gets +2/+2 and gains flying until end of turn. Draw a card. Activate only as a sorcery.

Sheoldred's Headcleaver

Menace
Toxic 2 (Players dealt combat damage by this creature also get two poison counters.)

Duress

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

Flensing Raptor

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Flensing Raptor enters, another target creature you control with toxic gets +1/+1 and gains flying until end of turn.

Dross Skullbomb

{1}, Sacrifice Dross Skullbomb: Draw a card.
{2}{B}, Sacrifice Dross Skullbomb: Return target creature card from your graveyard to your hand. Draw a card. Activate only as a sorcery.

Vat Emergence

Put target creature card from a graveyard onto the battlefield under your control. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Blightbelly Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Vanish into Eternity

This spell costs {3} more to cast if it targets a creature.
Exile target nonland permanent.

Duelist of Deep Faith

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
During your turn, Duelist of Deep Faith has first strike.

Planar Disruption

Enchant artifact, creature, or planeswalker
Enchanted permanent can't attack or block, and its activated abilities can't be activated.

Mandible Justiciar

Lifelink
Whenever another artifact you control enters, Mandible Justiciar gets +1/+1 until end of turn.

Whisper of the Dross

Target creature gets -1/-1 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Fleshless Gladiator

Corrupted — {2}{B}: Return Fleshless Gladiator from your graveyard to the battlefield tapped. You lose 1 life. Activate only if an opponent has three or more poison counters.

Swamp

Zealot's Conviction

Flash
Enchant creature
Enchanted creature gets +1/+1.
Corrupted — As long as an opponent has three or more poison counters, enchanted creature gets an additional +1/+0 and has first strike.

Vraska's Fall

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

Prosthetic Injector

Equipped creature gets +0/+2 and has toxic 1. (Players dealt combat damage by equipped creature also get a poison counter.)
Equip {1}

Dune Mover

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Dune Mover enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.