Before beginning the explanation, let's review the current situation of the Lostbelt where Naoki finds himself.
It all started fourteen thousand years ago, when an entity called the Harvester Star passed by Earth and dropped a Vanguard to destroy all civilizations on the planet.
That Vanguard was Sefar.
Its arrival nearly wiped out all existence on Earth. No god could stand against it. However, before it truly destroyed everything, someone wielding the Holy Sword forged by the planet defeated it.
That was Naoki's predecessor, Arthur's predecessor—the first Bearer of the Holy Sword.
This is the situation in Pan-Human History.
But in this Lostbelt, Sefar—who should have been defeated by the Holy Sword Bearer fourteen thousand years ago—was not defeated. This was because, at the critical moment, the six primordial fairies tasked with forging the Holy Sword slacked off instead of completing their work.
This fatal failure meant the Holy Sword wasn't born in time. Sefar wasn't defeated and destroyed everything on Earth.
This is the most fundamental cause of this Lostbelt's birth after the initial destruction.
Afterward, the six primordial fairies lived alongside the Horned God of the Celts, Cernunnos, who had returned from the Inner Sea of the Star, and the human Magus he brought with him.
Cernunnos, returning from the Inner Sea of the Star, carried the mission to make the six fairies aware of their sins. Thus, he continually admonished them to reflect. At first, the fairies did reflect, but over time, they grew impatient. Living constantly in the sea, they began yearning for land.
So, they poisoned Cernunnos, used his corpse as land, killed the human Magus, used his body as material to create humans, and lived with the descendants they birthed.
This was the beginning of this Lostbelt's revival after total destruction.
Setting aside the thousands of years that followed, the focus is on what happened around four thousand years BCE in Pan-Human History time.
Because the six primordial fairies committed an unforgivable original sin—and refused to acknowledge it—their descendants were also cursed and bore that sin.
To make the fairies aware of their sins, the Inner Sea of the Star—Avalon—sent a Paradise Fairy to Earth to save the sin-bearing fairies of Britain and urge them to repent.
That was Aesc, whose original name was Vivian.
The first place Aesc visited was the northernmost tip of the current British Lostbelt. A clan called the Rain Clan accepted her and let her spend a beautiful childhood. Upon learning the original sin committed by themselves and their ancestors, the entire clan expressed understanding and willingness to accept any punishment.
Thus, Aesc's childhood was spent in a warm, happy environment, giving rise to a thought different from her mission—she dreamed not of completing the Paradise Fairy's task, but of creating a Fairy Kingdom where anyone could live in peace.
But tragedy struck anyway. Since the Paradise Fairy bore the mission to make Britain's fairies repent, the fairies naturally hated her. The Rain Clan didn't tell other clans they had adopted the Paradise Fairy, so when the truth came out, the entire Rain Clan was annihilated.
Aesc was killed that day.
This is what should have happened in the early history—the first history that occurred in this Lostbelt.
But afterward—
"I from Pan-Human History came here." Aesc explained.
"From the memories I obtained, I from Pan-Human History arrived using technology called Rayshift about two thousand four hundred years from now. She seemed to have prepared for this from the start and knew everything that happens in this world from the beginning."
Naoki knew Aesc was talking about Morgan.
After the Seventh Singularity ended, Naoki never met Morgan again. She vanished from the world, as if evaporated.
(Now that I think about it, back then, Morgan had already left Pan-Human History and Rayshifted herself to this Lostbelt?)
As for why Morgan came here… Naoki didn't know. But he had a slight clue about how she knew of this place.
It was probably Merry's doing.
From Merry's frequent dream visits, Naoki knew all his memories had been seen by her. In many ways, Merry knew him best in the world. She knew everything about him.
This naturally included what he knew about the British Lostbelt. After learning it, Merry might have copied those memories without his knowledge and given them to Morgan.
The reason she did it was most likely—no, definitely—just for fun.
Then, as Naoki suspected, Morgan came to this Lostbelt after the Seventh Singularity. With ten years, it wasn't impossible for Morgan to find a way to the Lostbelt world.
"I received everything from my Pan-Human History self the night before the clan's annihilation. She left two messages stored in memory."
"One for me."
Aesc paused, imitating Morgan's tone as best she could.
"'I in the Lostbelt, I am you in Pan-Human History. I know everything you've experienced, everything you will experience. You will walk a different path from mine—a thorny road filled with suffering and betrayal. May what I prepared for you over ten years ease your troubles a little.'"
Ten years.
Naoki noted the timeframe.
That was the estimated period Morgan and Mordred disappeared. So she spent those ten years preparing for her Lostbelt self?
"And one for you—or rather, introducing you to me." Aesc continued. "'Besides that, according to my preparations, he will surely arrive in your world one day. The Bearer of the Star's Holy Sword who doesn't exist in your world—the World Savior. Though the timing is uncertain, he will definitely come to your side. When that happens, please make your request to him.'"
"'He is a man who won't refuse. As long as it's to save the world, he will surely fulfill your wish.'"
"—Those are the two messages left by my Pan-Human History self."
At this point, Aesc's face showed slight emotional turmoil. "That was over three thousand six hundred years ago… Since then, I've continued fighting to resolve the calamity while searching for you, continually awaiting your arrival."
"And now, I have waited for you."
The hope given three thousand six hundred years ago, the promise without real effect from that distant past, had finally become reality before Aesc.
"Natsukawa Naoki, Bearer of the Star's Holy Sword who doesn't exist in my world—please hear my request."
"Please save this Britain, fated for destruction, together with me."
"Please save this world, fated for destruction, together with me."