This information is subject to change with the release of the OFF prequel comic, coming alongside the Collector's Edition some time next year.
There was a world that existed before the world we see during OFF.
A little boy exists in this world named Hugo. We don't know how he got here or what he did. He appears old enough to walk and talk, looking somewhere in the mid-single-digits.
Hugo possesses some creative power. He creates Vader Eloha and The Batter to be his mother and father, and take care of him. We do not know if Hugo intentionally created them, or if it was an unconscious act. Hugo may have even created the old world.
At some point, some apocalyptic calamity happened in the old world.
We see the old world after this event in The Room, during "Chapter 4". The world left over is dark and gloomy. It appears starkly different from everything else we see in the game.
Whatever happened, it was so calamitous that nearly no one is left alive afterwards.
She's someone really important, you know. Once she's back she'll revive all of this, everything'll work again.
Hugo's mother, Vader Eloha, desires to create a new world for Hugo. She enlists three people to rebuild and rule the new world with her. The three begin their plans for what the new world will look like.
It is possible that she caused the apocalypse in the old world, although we don't know when that event occurred in relation to everything else.
Hugo's mother recognizes that Hugo is sick. His mother and father conclude that Hugo must stay inside, in his room.
At some time, Hugo befriends a cat named Pablo. Pablo promises to throw him a party when he recovers from his sickness. This information comes from the unreleased OFF prequel comic, "OF", that releases alongside the Collector's Edition. View preview
Hugo begins to stay inside due to his sickness. Hugo doesn't see his mother very much by this time. She is gone, left to create the new world... what exactly that entails is unknown.
Hugo dislikes the place where he's staying. He takes solace that his Papa, the Batter, is here. His Papa stays with Hugo to keep him company. Hugo's father plays with him, and gives him a comic book—"Panic in Ballville". Hugo's father tells Hugo that he must take pills for his sickness. Hugo does not like taking the pills.
Hugo spends his time drawing and sketching, and rearranging the chairs in his room. He draws the hallway leading to the outside, and draws spectres in the hallway.
With the permission of Hugo's father, he begins to go outside...
Hugo explores what's left of the world. He meets three new people: the Tall Mister, the Bird, and the Big Mister—that is, Dedan, Japhet, and Enoch. They recognize Hugo, probably learning of him through the Queen.
Hugo helps the future guardians, giving them things to help them in these "times of misery". They each make promises to Hugo once the new world is created...
It's gonna be great, you'll see! We'll ride pedalos together. Have ya ever ridden a pedalo? Bah, it's awesome, you'll see.
No worry shall reign in my kingdom, for I will wipe the tears off the faces of my subjects.
If you go look for someone to help me, I'll bake you some cakes! They are going to be delicious, you'll see. And we'll tell each other jokes.
At some point, Hugo's father leaves. We do not know why this happens, but Hugo writes a letter to his mother, asking her to come back soon.
The old world is completely destroyed. What remains is The Nothingness.
Queen creates the new world for Hugo as planned. Four zones are created, and the Queen's chosen guardians are put in charge of three of the zones. The four zones are created out of the nothingness.
Like all the guardians, it's my job to mold the Queen Mother's energy into a solid context. I am the living engine of zone 3. The Queen relies on us to create places for the people to live. We are a little like gods, drawing on the infinite power of the sun to sculpt our worlds out of the nothingness.
For she chose Three Guardians to rule some of the Zones.
In no particular order,
I believe that Pablo (the Judge) is Zone 0's guardian. While not stated in-game, he is the primary resident and the only other friend of Hugo from the old world.
The "Explanations" book in the Bismark library has a chapter on "The Four Zones". Some evidence for why Zone 0 is the fourth zone, and The Room is not, is that Zones 0, 1, 2, and 3 have unique title cards when you first enter, while The Room does not. Additionally, the Nothingness has red dots for Zones 0, 1, 2, and 3, while The Room has a white dot, signifying some kind of difference between them.
This would also fall in-line with what we know from the OFF prequel comic, where Pablo says he will throw Hugo a party, and that "by then, my Zone will be perfect!"
It is possible that Hugo created the plans for what the new world will look like, and that is why Pablo has his own (small) Zone, with no population, as it was intended for Hugo's party. This could be implied by the name of the song that plays during The Room's scribble-map, "A WHOLE NEW WORLD TO DRAW". (Remake name only)
Hugo is the guardian of The Room, evidenced by it only becoming purified after he is killed.
Over time, the lofty and virtuous goals of the three Guardians degrade.
Dedan indeed provides his people with jobs and security, like he said. But they are overworked, since the other zones all rely on Zone 1 to function.
Japhet becomes furious that the people of his zone do not recognize him as the one who provided everything for them. He also gets eaten by Pablo's brother Valerie at some point.
Enoch begins creating sugar from corpses, and feeding the sugar to the factory workers in massive quantities to keep them working.
At some point, the souls of those who died in the old world's apocalypse begin to haunt the new world. This may have been caused by the Queen, but we don't know for sure. This is hinted at in one of the Bismark books:
Arcane legends tell of the Queen, living by her father's side in the Room, engendering the phantoms to destroy the world that they themselves have created.
After the phantoms' arrival, The Batter, Hugo's created father, seeks to purify (and ultimately) destroy the new world. He claims that everything went wrong, as if the new world has failed its original design. He claims this to be his sacred mission, and his purpose.
It all went wrong. Time to forget about it and dream sweet dreams.
Escaping from your purpose is impossible.
It is possible, and perhaps implied, that The Batter was created by Hugo to end his sickness. He does this at first by giving Hugo pills, which doesn't work. Then he revisits this later, desiring to purify Hugo of his sickness... by killing him, and destroying the world that failed to protect him. This would, then, imply that the Queen was created to protect Hugo, explaining the orders to stay inside.
The Add-Ons that the Batter recruits as part of his mission are spirits that emerged from three promises that the three Guardians made to Hugo about what he'd get to see and do in the new world. These promises were left unfulfilled, because Hugo never got better. Instead, they become agents of the new world's undoing.
Zone 1's purification immediately spells death for the rest of the new world, even before you step into Zone 2. Without it, the other zones would stop receiving shipments of smoke to breathe, meat to eat, and metal and plastic to build with. Dedan's death is hardly justified, either — he wants to destroy the spectres, too, and is seen fighting them before his boss battle.
The battle with Dedan is the first indication in OFF that the Batter's mission isn't so righteous. The fact that his enemies are called "Guardians" makes it obvious in hindsight. If the Batter wanted to fix the world, he could have worked with Dedan to get rid of the spectres. But the Batter's mission isn't about the world's betterment. It's about the world's destruction.
Your choice at the end of the game decides the fate of the new world. If you side with the Batter, the new world is destroyed completely, with every Zone purified and empty. If you side with the Judge, the Batter dies, and Pablo returns through the purified zones back to Zone 0, presumably spending the rest of his days with Zacharie and Sugar (unless you defeated her).
There isn't really any conclusive information about Zacharie's past. We know that several characters from OFF are survivors of the old world's apocalypse. Zacharie is likely one of them, alongside Pablo, Valerie, and Sugar, all of which seem to reside (or used to reside) in Zone 0. However, there is one strange repeated story in the Bismark library that might be about Zacharie.
A long time ago, there lived an evil king with countenance so repulsive, he was called the Toad King. One beautiful day, a masked man presented hisself at the souvereign court, and spoke these words:"Good day, o evil monarch! Leave and return peace to thy people or taste mine blade and perish at its end."
The king reponded: "I am the king, and thou art my subjects. Thou art not to oppose mine will."
Thus, the masked man brandished his epee and killed the king. The End.
Another book in the library has this in its table of contents:
The Toad King and the Merchant
The only masked man we meet in OFF is Zacharie, who also happens to be the only merchant we meet in the game. There are no other fictional accounts in the library—it's filled with accounts of the Queen or the Guardians, all confirmed by story events. Zacharie is never seen with a sword in OFF, but he is represented with a sword in concept art, even though The Batter never battles him.
So... there was an evil king in the old world who Zacharie killed. That's at least something.
This king's death may have been the cause of the old world's apocalypse, which created a power vacuum after which the Queen was able to gather followers and take control.
However, if Zacharie was a just vigilante, you would expect him to oppose the destructive mission of The Batter. Instead, he assists throughout the whole endeavor. Maybe he sees the Queen as equally corrupt as the Toad King? He's mentioned to be the boss of the theme park in Zone 2, and seems very familiar with the shopping mall. We don't get any explanation on that, but he's at least been busy in the New World, too.
These are all new additions to the 2025 OFF remake. Basically all we can do is speculate.
The zodiac bosses, who I'll refer to as the "seraphs", only appear in three places:
Each of these places are colorless and empty areas, but when the Seraphs arrive, they bring color with them.
The seraphs speak in strange ways like riddles. I don't think they're from the new world. I think they're something like gods, or personified forces of nature. (Whatever nature means in the OFF universe.) Source and Cob, the first and last seraphs respectively, are even presented as manifestations of life and death! They seem to move in once the Batter begins emptying the zones.
Unfortunately I really don't have a good answer for this one, since no information is given in-game.