Chittering Skitterling

Corrupted — Sacrifice an artifact or creature: Draw a card. Activate only if an opponent has three or more poison counters and only once each turn.

Duress

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

Atmosphere Surgeon

Whenever you cast a noncreature spell, put an oil counter on Atmosphere Surgeon.
Remove an oil counter from Atmosphere Surgeon: Target creature gains flying until end of turn. Activate only as a sorcery.

Meldweb Strider

Vigilance
Meldweb Strider enters the battlefield with an oil counter on it.
Remove an oil counter from Meldweb Strider: It becomes an artifact creature until end of turn.
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)

Transplant Theorist

Whenever Transplant Theorist or another artifact enters the battlefield under your control, you may draw a card. If you do, discard a card.
{2}: Put target card from your graveyard on the bottom of your library.

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Testament Bearer

When Testament Bearer dies, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Swamp

Sheoldred's Headcleaver

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

Vat of Rebirth

Whenever another artifact or creature you control is put into a graveyard from the battlefield, put an oil counter on Vat of Rebirth.
{2}{B}, {T}, Remove four oil counters from Vat of Rebirth: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Eye of Malcator

When Eye of Malcator enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
Whenever another artifact enters the battlefield under your control, Eye of Malcator becomes a 4/4 Phyrexian Eye artifact creature until end of turn.

Mesmerizing Dose

Enchant creature
When Mesmerizing Dose enters the battlefield, tap enchanted creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Enchanted creature doesn't untap during its controller's untap step.

Tamiyo's Logbook

{5}{U}, {T}: Draw a card. This ability costs {1} less to activate for each other artifact you control.

Necrosquito

Flying
Necrosquito enters the battlefield with two oil counters on it.
Necrosquito gets +1/+1 for each oil counter on it.
Whenever another creature or artifact you control is put into a graveyard from the battlefield, put an oil counter on Necrosquito.

Font of Progress

Font of Progress enters the battlefield with two oil counters on it.
{3}, {T}: Target player mills X cards, where X is the number of oil counters on Font of Progress.

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap Staff of Compleation.

Island

Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Aspirant's Ascent

Until end of turn, target creature gets +1/+3 and gains flying and toxic 1. (Players dealt combat damage by that creature also get a poison counter.)

Vraska's Fall

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

The Monumental Facade

The Monumental Facade enters the battlefield with two oil counters on it.
{T}: Add {C}.
{T}, Remove an oil counter from The Monumental Facade: Put an oil counter on target artifact or creature you control. Activate only as a sorcery.

Ichor Synthesizer

Whenever you cast a noncreature spell, put an oil counter on Ichor Synthesizer.
As long as Ichor Synthesizer has four or more oil counters on it, it gets +2/+0 and can't be blocked.

Atraxa's Skitterfang

Atraxa's Skitterfang enters the battlefield with three oil counters on it.
At the beginning of combat on your turn, you may remove an oil counter from Atraxa's Skitterfang. When you do, target creature you control gains your choice of flying, vigilance, deathtouch, or lifelink until end of turn.

Chrome Prowler

Flash
When Chrome Prowler enters the battlefield, tap target creature an opponent controls.

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.)

Offer Immortality

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)