The so-called progenitors of humanity were lifeforms born at the dawn of this planet. They possessed their own unique path of development and energy systems—what we know as natural energy or senjutsu.
Humanity's progenitors—or perhaps by their more familiar name—Sages.
Most of them were not human at all, but ancient beings who had completely mastered senjutsu or natural energy.
Examples included the Great Toad Sage of Mount Myōboku, and the White Snake Sage within Ryūchi Cave.
When Kaguya Ōtsutsuki first descended and began planting the God Tree to drain the Earth's energy, the two sides became mortal enemies.
The God Tree's plunder left less than a fraction of the planet's natural energy remaining, nearly severing the world's very lifeline.
Only the mysterious Three Great Sage Lands, and a few places humans could never tread, still retained the conditions necessary to cultivate natural energy.
From one perspective, Kaguya was the invader, while the sages were defenders—an ethical divide seemingly clear enough.
Yet after giving birth to Hamura and Hagoromo, Kaguya's thinking began to shift in strange ways. Her stance changed abruptly, and she even grew a will to resist her own clan. Having eaten the chakra fruit, she objectively possessed the power of a god. Thus she struck a compromise with humanity's progenitors: she would help Earth's natives resist the main branch pursuers, and gradually return chakra to the world.
But among the sages, opinions of Kaguya differed sharply. Some advocated working with her to face the even greater threat of the main family's arrival. Others pushed to seal her away and use the released chakra to strengthen the planet's native life against future invasions.
The latter group's leaders were the Three Great Sage Lands.
Ultimately, those who sought to oppose Kaguya succeeded in driving a wedge between her and her sons, Hagoromo and Hamura, leading them to seal away their own mother.
Meanwhile, the sages who favored compromise devised a more complicated solution. They used an intricate senjutsu to separate the purest yin and yang forces in the world, infusing them into the bodies of the Sage of Six Paths' two sons, Indra and Asura. This would ensure they battled one another for generations—yet hidden within was a faint chance for Kaguya's resurrection. It soothed the warmongers' fury while preserving a vital card for the day they might need to resist the main family.
Even Black Zetsu had unknowingly been made a pawn in this game.
When Hamura, during his long vigil on the moon, came to understand all of this through the will of the sealed Kaguya within, it was already far too late. His mind was consumed by vengeance.
For that vengeance, he created the Tenseigan—yet in the original world, no clansman capable of awakening it ever appeared. He met his end at the hands of Naruto Uzumaki and Hinata Hyūga.
As an invader's descendant, Satsuki had no right to judge either side's position.
But her soul was that of an outsider, able to understand both. And for that reason, she knew: this was a hatred that could never be easily erased. Though she was innocent in action, her bloodline alone gave her a responsibility she could not escape.
Thus, her enemies might not be limited to the Ōtsutsuki main family. If she mishandled matters, she could find herself opposed by the hidden forces that had remained in Earth's shadows since ancient times.
And this giant Tenseigan was not only a killing tool Hamura had intentionally revealed to his clan, but also a key to the eventual awakening of the one destined to defy fate.
As if on cue, Hamura's true body slowly emerged from within the giant Tenseigan—appearing far younger than when she had last seen him in the underground tomb.
Long pale hair draped down his back, twin horns crowning his head. His white eyes, framed by heavy shadows, lent him an eerie allure—but the cold, detached face of the Ōtsutsuki clan robbed him of any warmth.
"I trust you now understand the nature of what we face," Hamura began. "My brother and I, swayed by their words, sealed away our own mother. This led to the gradual weakening of our bloodline's power. In the foreseeable future, our lineage will fade from the world's stage—or become mere puppets under their control. Just like my two nephews."
His voice rose. "My clanswoman, the trial you face is not a single visible foe. It is the enmity of the entire world, and the struggle of standing utterly alone. Even so, will you remain steadfast—willing to live and die without regret?"
"Lord Hamura." Satsuki's feelings toward this sage were deeply conflicted.
With the Ōtsutsuki main family as the true enemy, she had no wish to make others her foes.
"There is room for reconciliation between us and the sages."
Hamura's pale eyes widened. An oppressive force surged through the space. "Satsuki Ōtsutsuki, do you understand what you are saying? Would you make the sacrifices of our lunar Ōtsutsuki in vain? Will you watch as our kin on Earth are manipulated by those sages—until they are erased?"
But Satsuki had already decided. She would not retreat. She faced Hamura, his nine Truth-Seeking Orbs arrayed for battle, and gave a slight bow before straightening. Pride returned to her golden eyes.
"Forgive my bluntness, but your rage has burned away your reason. Here, now, Lord Hamura," her eyes shifted into the six-petaled golden form—the legendary Tenseigan, "it is unwise to threaten me."
Under that gaze, Hamura—six paths level for untold years—felt true dread for the second time in his life. The first had been in the presence of his mother, Kaguya Ōtsutsuki.
Through Hamura's Byakugan, her overwhelming ocular power nearly took physical form, twining into the image of a candle-bearing dragon coiled around her. Under its stare, he could not even move his body.
Even his nearly indestructible Truth-Seeking Orbs began to show signs of collapse under the energy her eyes radiated.
"Impossible... How has your evolution been so fast?" Hamura stared in disbelief. Then awe crept into his voice. "This... this is the power of the Tenseigan?"
After feeling it for himself, his expression shifted through many shades. At last, he exhaled slowly and lowered his head in concession.
Against Satsuki's current strength, even he held no advantage. If they fought, both would lose.
"Very well, Lord Hamura. I will protect the bloodline of our branch family with all my strength—and I will destroy those of the main family."
That was her promise.
Hamura could only nod, reluctant but resigned. He gave her one last look before his form faded back into the giant Tenseigan.
At that moment, Satsuki fully claimed the Ōtsutsuki clan's treasured legacy—the giant Tenseigan.
Raising a hand, she drew it toward her. The massive eye shrank rapidly, flying obediently into her palm. It poured vast ocular power and Ōtsutsuki chakra into her, helping her newborn Tenseigan through its awakening.
Feeling the unending surge of chakra and ocular might, she channeled it into her eyes. Lifting her head, she met the gaze of the dragon-shaped energy form around her. In its eyes, she thought she saw a trace of reverence.
She tossed the Tenseigan to the energy dragon. Its form shifted dramatically, strengthened by the infinite chakra and ocular force, moving closer to the legendary miniature form of the Candle Dragon who controls day and night in the Classic of Mountains and Seas.
The energy was too vast to draw back into herself. Even her control could not contain it. Lightning-like manifestations of pure energy danced over her form. Space rippled, her outline expanding in afterimages that faded and returned—clear signs of energy overflow.
She resolved to master this power before returning to Earth, at least enough to control and conceal it.
In the blink of an eye, space around her shifted. She stepped into the lunar castle.
Before her lay Toneri Ōtsutsuki, still unconscious, cheeks puffed slightly in his slumber. Puppets stood ready at his side to knock him out again if needed.
It seemed Toneri's days had not been pleasant.
At that moment, her system issued its second mission since arriving here:
"Main quest updated: Objective—become the strongest being in this world (progress: ??). Prerequisite met. New quest unlocked: Form the strongest faction across all realms of this world."