The Infinite Cosmology of Phantasy Star Online 2

PSO2 builds its cosmology on the multiverse theory, the Many Worlds Interpretation of quantum mechanics, and the metaphysics of the Akashic Records. Central to this framework is Xion, the omniscient observer and recorder of all existence.

The result is a cosmology where universes and timelines branch infinitely, producing countless worlds, all woven into the Neverending thread of history.

1. The Multiverse is Canon in PSO2

PSO2 has a multiverse. In particular, it is outright stated to run on multiverse/parallel world theory:

  • Xiera explains the multiverse theory:
     Sword Dance of Black and White (PSO2 x SAO Crossover)


     Xiera: “Do you know of the parallel universe theory? It’s also known as a multiverse or parallel world, but basically...
    The idea is that another universe exactly like our own exists out there somewhere.
    In fact, there have been reports of teleporters going haywire in the past, landing ARKS operatives in unknown worlds.”

  • Alma on the multiverse bound to the Records:
     Cutscene (Episode 5)
  • Ethan: I thought I'd gotten used to all sorts of freaky happenings, but how do you prepare for going to a different world…
  • Karen: I'm Karen Erra. Just like Ethan here, I've come from a different world.
  • Karen: It feels a bit different, but the Photons in this world and the Photons in ours are essentially the same.
  • Karen: Photons are probably the reason why Ethan and I got lost. ...Or should I say, they guided us here?


  • Parallel Worlds as a mechanic:
    Players can be transported into parallel worlds randomly and indefinitely. These areas are locations from the main universe that are completely altered or feature differences in another universe.

Imgur Evidence.

2. Xion’s Omniscience and Infinite Possibilities

Xion is directly tied to the Akashic Record, embodying knowledge across all timelines. Multiple quotes reinforce her omniscience:

Luther’s Goal:

Luther: Why did this ocean of knowledge come to be? To preserve the past and foresee the future... To be, quite simply, all-knowing! The Photoners--no, I myself have long sought to understand all that this represents! ARKS, the Falspawn... All of my research and experiments have been to bring me here and now! It was all just to understand her. To become one with her. And at last, I shall! The two of us will be one! I will comprehend the whole of creation!”

https://phantasystar.fandom.com/wiki/Luther

Luther: Xion and I will never be apart again. Not even for a breath.

Luther: I've finally come to understand her, you see. Now, her and I are to become one, and I will at last gain true omniscience!

Luther: And then... Then, at last, it will be mine! Infinite knowledge! Omniscience! Omni... Wait... What am I.

https://phantasystar.fandom.com/wiki/The_Man_Who_Would_Know_All

➡ Luther seeks to merge with Xion to gain infinite knowledge and become omniscient, showing that Xion herself possesses that boundless awareness.

Xion’s Statement to the Protagonist:

Xion: Go and weave a timeline beyond the reaches of omniscience.

Japanese Dialogue of An Encounter with Xion:

無限にも等しい思考の末 わたしが見出した事象を。
“As the result of thoughts tantamount to infinity, I discovered these phenomena.”

あらゆる偶然を演算し、計算しここに残す。
“I have calculated all contingencies/possibilities and recorded them here.”

Alternate Translation:

無限にも等しい思考の末 わたしが見出した事象を。The phenomenon I discerned, at the end of thought equal to infinity.

あらゆる偶然を演算し、計算しここに残す。I compute and calculate every contingency, and leave it here.

Xion explicitly frames her discoveries as arising from “thoughts tantamount to infinity” (無限にも等しい思考). Given her nature as an omniscient observer tied to the Akashic Records, this phrase is not poetic exaggeration but a literal reflection of her capacity: infinite cognition applied across infinite scenarios. This infinite reasoning directly informs her subsequent statement that she has “calculated all contingencies and recorded them here.”

Therefore, if her process of thought is infinite, and her calculations encompass all contingencies/possibilities, then the outcome she surveys cannot be a finite set of options. Instead, it represents endless, branching possibilities across timelines and universes. Xion’s infinite thought is the very mechanism by which she grasps the infinite potentialities of the multiverse:

  •  “This is but one outcome. Only one of many, might I add.
    All possibilities are already woven together. The answer lies in your future.”

  • Fan Translation vs. NA Localization:
     Widely trusted fan translation by the Arks-Layer team renders one of Xion’s lines as:

    “That is why I have calculated the     endless possibilities and cataloged them here.”

https://youtu.be/17Q9-SDGB9Y?t=85


This is more accurate than the NA localization’s interpretation because the Japanese nuance implies limitless branching potential, not a closed set. It also compliments the original statement regarding Xion's infinite computation of possibilities since the endless possibilities are the direct result of her infinite thought process.

NA localization is also notoriously flawed and changed much of the meanings, texts, and names (which often differ radically from JP):

  • Poor translation: https://www.reddit.com/r/PSO2/s/ilC2od6PNg
  • NA translation contains several errors, ranging from grammatical to outright misinterpreting voice lines: https://www.reddit.com/fy5vkkw?utm_source=share&utm_medium=android_app&utm_name=androidcss&utm_term=1&utm_content=2
  • More errors: https://www.reddit.com/fy67fdg?utm_source=share&utm_medium=android_app&utm_name=androidcss&utm_term=1&utm_content=2
  • Generic vs Unique Text from fan translation: https://www.reddit.com/fy64aps?utm_source=share&utm_medium=android_app&utm_name=androidcss&utm_term=1&utm_content=2

This makes clear that possibilities in the context of timelines and universes are endless, not finite. It also makes sense narratively. Xion is attempting to defy fate and find a future free from the presence of the Profound Darkness. Therefore, she calculates every single possibility, which came about after infinite thoughts/endless thinking, that could lead to her desired future.

3. Diverging Streams: The Law of Infinite Branching

The most explicit cosmological law comes from Tragedy or Liberation?:

Xion:

“The new flow has become a diverging stream. However, it is a model that will affect even the main river.”

Original Japanese:

  • 一つの流れが行き着きし先で
  • 数多の傍流は生まれ出る。
  • それは摂理であり、定理だ。
  • その一つ一つの結末に
  • 深意的な価値はほとんど存在しない。

ChatGPT Translation:

  • At the point where a single flow reaches its destination,
  • countless tributaries are born.
  • That is providence, and it is a theorem.
  • Within each of those individual endings,
  • there exists almost no profound value.

DeepL Translation:

  • At the destination of a single stream
  • Countless tributaries are born.
  • It is providence, a theorem.
  • In each and every one of those endings
  • There exists little profound value.

Third translation by a native-speaker.:

- 一つの流れが行き着きし先で At the point where one stream comes to rest,  

- 数多の傍流は生まれ出る。 countless tributaries/branches are born.  

- それは摂理であり、定理だ。 This is a law of nature, a principle.  

- その一つ一つの結末に  At the end of each of them,

- 深意的な価値はほとんど存在しない。 there is scarcely any profound value to be found.

Fourth Translation by a user who both taught Japanese and works in a Japanese team of an international company:

Originally translated the text to:

  • Before a stream reaches its destination,
  • many of its tributaries will be born,
  • That is a fact of nature, a theorem.
  • And at each of their ends,
  • almost nothing of significant value can be found.

However, they then agreed that the word “countless” is more appropriate considering the tone of the text, the type of words utilized, and the refined nature of the author's way of speaking. The translator stated that “many tributaries” is too simple and cheapens the speaker's language and intent, which is why “countless” is more in line with the refined and complex nature of their speech. This is completely consistent with Xion's character given she speaks in a very formal, machine-like manner befitting her status as the omniscient keeper of the library that is the Akashic Records.

All four translations agree: countless tributaries emerge from the main river at its endpoint.

  • The river = a universe’s main timestream.
  • Tributaries = diverging timelines/worlds actualized at branch points.
  • 数多 (amata) = countless, innumerable — not simply “many” but indefinite/infinite.
  • Declared both a law of nature (摂理) and a theorem (定理), making this branching inevitable and infinite which is consistent as Xion herself says that the branching of possibilities is inevitable.

Thus, every timeline’s “end” is not an end, but the birth of infinite new streams. This ties well with the idea that each universe has its own “stream” in reference to their timestreams and histories. It is from these streams that countless others are born.

4. The Neverending Thread of History

Episode 6 describes the Akashic Records as:
 Cutscene Link

“This is the light of the Akashic Records. From it is spun the Neverending thread of history. It is the form of the world you created.”

To provide context, every universe and its history is fated to repeat in an infinite cycle, which is why Xion wanted the protagonist to find deviating timelines and branches to reach a good future. However, the line in particular doesn't just apply to one universe’s cyclical history:

  • If this referred only to a single universe’s cyclical history, it would contradict the tributary law of infinite branching and the multiple worlds bound to the Akashic Records.
  • Instead, the Neverending thread must be understood as the infinite weaving of countless timelines across multiple universes.
  • Supporting this, Xion elsewhere distinguishes that different universes are bound by different threads, all converging into the Records which is the overarching Neverending thread to which all worlds are bound.

Thus, the “Neverending thread” is not closed repetition, but the eternal expansion of histories across infinite worlds.

5. The Protagonist as a Multiversal Vessel

The protagonist’s uniqueness is explicitly tied to their multiversal nature:

This confirms:

  • Each universe alone is cyclical, bound to repeat.
  • The threads binding universes are what allow escape from a single cycle.
  • Each universe can spawn a countless/endless number possibilities and divergent streams, with only the future being the only possibility that lies beyond even Xion’s omniscience relative to the Akashic Records.
  • The protagonist embodies this multiversal linkage, acting as the vessel of all worlds bound by the Records.

6. Reconciling Threads and Infinity

  • The Neverending thread refers to the Akashic Records’ eternal weaving of histories.
  • Different threads bind each universe, representing distinct but interconnected world-histories.
  • The tributary law guarantees that each thread produces countless offshoots, expanding the Records infinitely.

Thus, the system is:

  • Single universe = cyclical history (closed loop on its own).
  • Akashic Records = infinite multiverse (opened by countless tributaries/threads and all worlds are bound to it).
  • Protagonist = vessel spanning all universes, able to transcend cycles and influence infinite branching.

Conclusion

PSO2’s cosmology explicitly establishes an infinite multiverse, supported by:

  1. Direct references to multiverse theory and parallel worlds.
  2. Alma’s statement that all kinds of worlds exist, each with their own timestream/histories and thus, their own branching timelines.
  3. Xion’s omniscience, infinite knowledge, and calculation of endless possibilities, confirming limitless potential for worlds.
  4. The tributary law: From the  main streams of the different universes, countless new ones are born.
  5. The Neverending thread of the Akashic Records, woven across universes, not confined to one.
  6. The protagonist’s existence as a multiversal vessel, transcending the repeating cycles.

Together, these make clear that:

  • Each universe can spawn divergent streams.
  • The Akashic Records span all universes and is the thread from which all histories and worlds are spun.
  • The multiverse is infinite, ever-branching, and neverending.