At a time like this—
There was no way Emiya Shihara could be allowed the luxury of quiet contemplation.
How could Black Zetsu, who had lived for over a thousand years, not know exactly what to do?
When someone is confronted with a truth too shocking to comprehend, the mind becomes especially vulnerable—susceptible to paranoia, delusions, and even spiraling into apocalyptic conspiracy theories.
And in moments like that…
No matter what further evidence this person might receive in the future, the seed of that catastrophic idea would be impossible to uproot.
Black Zetsu knew this all too well—
Because it truly did harbor a plan to destroy the world.
And given that Emiya Shihara was born in the ancient era and already possessed knowledge most couldn't fathom, letting his imagination run wild now might very well lead him to stumble upon the real reason for Ōtsutsuki Kaguya's disappearance.
It had to seize this moment.
It needed to implant its own version of events deep within Shihara's mind, to make him willingly accept its truth, to let himself be reshaped by the narrative Black Zetsu spun—until he believed it completely.
"Let me finish."
The words rang oddly familiar to Black Zetsu.
That's right—Emiya Shihara had just said the very same thing.
What a twist of fate.
And so, Black Zetsu, mirroring Shihara, began to spin a story—a slightly embellished, carefully tailored version of events.
"Back in our time…"
"You must've heard the legend of the God Tree."
"In the age of antiquity, the God Tree appeared in this world. It became an object of worship for humanity. Alongside it descended Kaguya—venerated as the Rabbit Goddess."
"But…"
"What you don't know is…"
"Even then, humanity was locked in endless conflict."
Black Zetsu pushed its mind to the limit, working hard to paint its mother in a more virtuous light:
"In their suffering, people prayed to Kaguya for salvation. She heard them. She used the power of the God Tree to bring peace to a war-torn world…"
"However…"
"That was not the end."
"Even though she wielded godlike power…"
"Even though her strength was as brilliant as your own wisdom in human experimentation…"
Yes—Black Zetsu had learned a few tricks in its long life. When fabricating a tale, it helped to draw emotional parallels, to flatter the listener so they'd empathize more deeply.
"Could it be…"
Shihara furrowed his brow in thought.
"Exactly."
Black Zetsu didn't wait for him to voice his guess—it pressed on.
"There were too many humans in the world."
"Kaguya wanted to share her power—her chakra—but only with those of noble spirit. People like you. She hoped such chosen ones could help ease the world's suffering…"
"Me?"
Emiya Shihara shook his head, rejecting the praise.
"I'm not so noble. I was just lucky—fortunate enough to gain power from the God Tree's remnants. I only want to use it to help others, the way the Rabbit Goddess once did."
"There's no need for false humility."
Black Zetsu refused to let him brush it off.
"I've wandered this world for a thousand years. I've never seen even a shadow of someone like you."
"Men of your caliber are vanishingly rare."
It sighed, then flowed smoothly back into the tale.
"But Kaguya knew too well how dangerous chakra could be. She believed its power shouldn't be given lightly—not if it might be misused to commit evil."
"That's only natural."
Shihara nodded in agreement, visibly approving of Kaguya's caution.
"People of true virtue are always few and far between…"
"Which is why her plan didn't go smoothly."
"Even so, it was no real obstacle to her."
"Kaguya had a long life ahead of her—endless time to find those worthy of inheriting her power."
"She was right to be careful."
"If chakra were handed out indiscriminately…"
"Indeed…"
Black Zetsu sighed again, as if recalling some distant sorrow.
"But her two sons didn't share that belief…"
"Two sons?!"
Shihara reacted sharply—this was new.
"That's right."
Black Zetsu's voice grew cold.
"Besides the Sage of Six Paths—Ōtsutsuki Hagoromo—Kaguya had another son: Ōtsutsuki Hamura."
"Both of them were born with chakra already flowing through their veins. So, to them, it didn't feel special. They believed their mother should share her power with the world, and let humanity decide its own fate…"
Black Zetsu treaded carefully.
It didn't want to slander Hagoromo too much—after all, he lived in the same era as Shihara.
But it knew: what it had said was already enough to plant suspicion.
"That…"
Shihara's brows knitted again, clearly unsettled.
"Distributing power so destructive to unprepared people… That seems hopelessly naïve."
"Exactly."
Black Zetsu agreed wholeheartedly, then continued with a quiet intensity.
"And now we see the consequences of that naivety."
"That childlike belief—"
"It was rejected by Kaguya."
"She was stronger than anyone. She had lived far longer than anyone. Her vision and wisdom far exceeded her sons'. She could foresee what we now endure."
…
The Rabbit Goddess?
Visionary? Wise?
Was Black Zetsu actually being sincere?
Shihara couldn't help but wonder if the creature was taking this opportunity to embellish things a little too much.
Still, he didn't call it out. Not now.
Instead, he put on a look of admiration.
"No wonder people of our time never forgot the God Tree… or the Rabbit Goddess who guarded it."
…
Black Zetsu felt a flicker of guilt—but only briefly—before diving back into its tale.
"What's tragic is that her sons couldn't comprehend their mother's greatness."
"Kaguya had long distanced herself from the world. She rarely spoke to anyone. And she had spoiled her sons too much—she lacked the sternness a mother sometimes needs."
"The two boys believed they knew better."
"They thought they could save humanity by taking the power she gave them—and turning it against her."
"You mean the cataclysm that nearly destroyed the world?"
Shihara's expression darkened.
That ancient catastrophe was still spoken of with trembling voices—passed down through generations since the time he had first awoken in this world.
"Yes."
"That was the war."
Black Zetsu nodded solemnly, assigning blame with a well-practiced ease.
"The two brothers, now grown, unleashed their chakra for the first time."
"They never realized how terrifying that power truly was."
"A single blow from them could kill countless people."
"It was disaster made flesh."
"Exactly what Kaguya had feared—the reason she didn't want chakra to spread."
"She didn't want to fight her sons. But when she saw the world torn apart… when the very people who worshipped her were dying in the shockwaves…"
"It broke her heart."
"Innocents with destroyed homes, followers lost in the chaos… And to top it all off, her most beloved sons had become her enemies."
"The Rabbit Goddess couldn't bear it anymore…"
"So in the end—she chose to yield."
Black Zetsu paused.
It gazed at Shihara, who now sat fully captivated by the story. Only then did it speak the tale's grim conclusion.
"Eventually…"
"The war ended."
"Though she was far stronger, Kaguya was sealed away by her own children."
And then, with a bitter chuckle, Black Zetsu added one final twist:
"They feared that after they died, she might reclaim the chakra they had scattered."
"And so…"
"The Rabbit Goddess vanished from the world."