Phyrexia: All Will Be One (ONE) — Set Guide

For years, the Phyrexians were the looming threat - the horror on the horizon. Phyrexia: All Will Be One (ONE) is the set where the horizon finally arrived. Released in February 2023, ONE takes us to New Phyrexia itself, in the middle of the Phyrexian Invasion arc that had been building across multiple sets. It's a 479-card set, and it leans hard into everything that makes Phyrexia Phyrexia: oil, corruption, bodies rebuilt into something terrible, and the cold certainty that everyone will be made perfect - whether they like it or not.

What is Phyrexia: All Will Be One?

Phyrexia: All Will Be One is a premier booster set released in February 2023, carrying the set code ONE. With 479 cards, it sits comfortably in the large-set range and is part of the Phyrexia story arc that began in Dominaria United (2022) and continued into March of the Machine (2023).

ONE is set entirely on New Phyrexia - the plane once known as Mirrodin, which was fully consumed and transformed by Phyrexian corruption over the course of Magic's history. The set was legal in Standard on release and is also playable in Pioneer, Modern, Legacy, Vintage, and Commander.

Format check: ONE rotated out of Standard in 2024 as part of the standard two-year rotation cycle. It remains legal in Pioneer and all eternal formats.

Themes and mechanics

ONE is built around two interlocking mechanical identities: poisoning your opponents and generating value through damage dealt. Both feel thematically on-point - Phyrexians don't just kill you, they infect you.

Toxic - poison, refined

Toxic is the headline new mechanic. A creature with toxic N gives the player it damages a number of poison counters equal to N, in addition to its normal combat damage. This is a refined, more controlled version of the older infect mechanic - creatures with toxic deal normal damage to life totals, but also stack poison counters on top.

Ten poison counters still means you lose the game, same as always. Toxic just gets you there without the all-or-nothing feel of infect, where a creature that dealt zero life damage still put you on a clock.

Rules note: Toxic only triggers on combat damage to players. Spells and abilities that deal damage don't trigger toxic. Keep that in mind when evaluating combat tricks and pump spells alongside toxic creatures.

Corrupted - a reward for landing poison

Corrupted is a new keyword condition, not an ability in itself. Cards with corrupted abilities check whether an opponent has three or more poison counters, and if so, they turn on a bonus effect. Three is a meaningful threshold - it's achievable in the early game with a toxic creature or two, but it rewards you for pressing the poison plan rather than just dabbling in it.

Together, toxic and corrupted create a push-pull tension that shapes the whole set: are you committing to the poison plan hard enough to turn on your corrupted payoffs, or are you hedging and leaving value on the table?

Proliferate - a returning engine

Proliferate returns here, and it fits like a glove. When you proliferate, you choose any number of permanents and players with counters on them, then add one more counter of each kind already there. In the context of ONE, this usually means adding poison counters to opponents and oil counters or +1/+1 counters to your own things.

Proliferate had previously appeared in Scars of Mirrodin block (2010-2011) and War of the Spark (2019). Its return to New Phyrexia is thematically perfect - and mechanically powerful in Limited.

Oil counters - Phyrexian fuel

A number of cards in ONE use oil counters as a resource, entering with a set number and spending them for effects. These aren't a keyword mechanic, just a flavourful counter type used throughout the set. They reward careful resource management and synergise with proliferate in satisfying ways.

Planeswalker themes

ONE is also notable for featuring several compleated Planeswalkers - beloved characters who have been converted into Phyrexian agents. These cards have a unique mechanic: you can pay life instead of coloured mana during casting, but doing so means the Planeswalker enters with fewer loyalty counters. It's a clean expression of the story's central horror: power at the cost of your self.

Limited and Draft

ONE's Limited environment is built around a clear central question: how committed are you to the poison plan?

Draft and Sealed in ONE tend to reward players who lean into toxic early and build around reaching the corrupted threshold. Because corrupted requires three poison counters on an opponent, decks that mix poison with non-poison strategies often find themselves in an awkward middle ground - they're not applying enough pressure to turn on corrupted, and they're not dealing enough regular damage to close out games the old-fashioned way.

The format has a reputation for being moderately fast. Aggressive toxic decks - particularly in white and green, or white and black - can apply pressure quickly and use proliferate to push opponents to lethal poison before they stabilise.

Proliferate effects are among the most coveted picks in the format, because they accelerate poison clocks, grow your own threats, and charge up oil-counter cards simultaneously. A well-timed proliferate in the mid-game can end a stalled board state immediately.

Key Limited archetypes (as broadly observed at release):

• White-Black toxic aggro - the most straightforward poison deck, with efficient toxic creatures and removal
• White-Green toxic midrange - bigger bodies with toxic, backed by proliferate
• Blue-Black control/tempo - leveraging corrupted payoffs and card advantage after establishing poison early
• Red-based artifact aggro - using oil counters and artifact synergies for a more traditional damage plan
• Green-X ramp into large threats - less focused on poison, more on outscaling the board

Notable cards and impact

The source material available doesn't give me a complete breakdown of every format staple from ONE, so I'll flag what's confirmed and note where I'm working from general knowledge rather than primary sources.

The Welcome Booster for ONE includes several cards as teaching tools, which gives us a window into what Wizards considered representative of the set's identity. Tyrranax Atrocity appears as the showcase for toxic - a common Phyrexian Dinosaur Creature that puts the mechanic front and centre. Ambulatory Edifice demonstrates additional costs, and Cephalopod Sentry shows off flying, multicolor, and colored artifacts - all of which are real threads in the set's fabric.

ONE also introduced or featured compleated Planeswalkers, which are mechanically distinct from any previously printed Planeswalker cards. The life-for-loyalty-counters trade-off created some genuinely interesting deckbuilding decisions in Constructed formats at the time of release.

I'd recommend checking current format ban lists and tournament data for the most up-to-date picture of which ONE cards are format staples or have been restricted - the competitive landscape shifts faster than any set guide can track.

Lore and setting

The plane of New Phyrexia was once Mirrodin, an artificial metallic world created by the golem Karn. The Phyrexians - led by Elesh Norn, Grand Cenobite - completed their conquest of Mirrodin during the Scars of Mirrodin block (2010-2011), renaming it New Phyrexia and beginning their expansion outward.

Phyrexia: All Will Be One picks up with the Phyrexians at the height of their power, preparing to invade the multiverse. The plane is divided into five sections (Phyrexia's equivalent of Mirrodin's five suns), each controlled by a different Praetor - the great leaders of Phyrexian society. Elesh Norn rules the white-aligned Mycosynth Gardens. Jin-Gitaxias governs the blue sphere of knowledge. Urabrask, the red Praetor, is a more ambiguous figure in this story - a Phyrexian who is not entirely aligned with Elesh Norn's goals. Sheoldred controls the black domain. Vorinclex rules the green wilds.

The story arc in ONE involves a team of Planeswalkers who have infiltrated New Phyrexia on a desperate mission, and several of them do not make it out unchanged. The compleation of major characters - some of Magic's most beloved figures - made this one of the most emotionally impactful sets in recent memory. I won't spoil exactly who, but the set earned its grim reputation.

Lore aside: The phrase "All will be one" is Phyrexian doctrine - the belief that all living things should be unified through compleation into a single, perfect existence. It's a villain ideology with genuine internal logic, which is part of why Phyrexia works so well as an antagonist faction. They genuinely believe they're helping.

Set legacy

Phyrexia: All Will Be One landed at a moment when Magic's storytelling was operating at high stakes, and the set delivered. The compleated Planeswalker mechanic was a genuine design achievement - mechanically representing story trauma in a way that felt earned rather than gimmicky.

Toxic as a mechanic addressed long-standing community frustration with infect. Infect's all-or-nothing nature made it feel oppressive in formats where it was legal; toxic kept the flavour and the poison-counter win condition while making creatures feel fairer in combat. Whether that fully solved the problem is something reasonable players disagree about, but it was a thoughtful attempt.

Proliferate's return was widely praised in Limited, where it created satisfying decision trees without feeling overpowered.

ONE is also remembered as the calm before the storm - it sets the stage for March of the Machine (2023), where the invasion the Phyrexians were preparing actually happens across multiple planes simultaneously. As a piece of a larger narrative, ONE does exactly what it needs to: it makes you believe the threat is real, and it makes you feel the cost of what's coming.