Black Zetsu Encountered Too Brilliant a Pawn in Its Lonely Youth

"It really was him..."

Black Zetsu felt somewhat conflicted.

It was a conflict tinged with pleasure and unease.

Although Shirou Emiya appearing in this era was an accident, and although he had ultimately betrayed Black Zetsu in the Ancient Era, Black Zetsu still missed the days when it had worked with Shirou Emiya.

It was a strange feeling...

Like how, when life was at its lowest, one should never meet someone too dazzling.

Whenever Black Zetsu thought of Shirou Emiya, it recalled their first encounter.

Back then...

Shirou Emiya had been trying to assassinate Indra.

Back then...

Indra had only possessed the Three-Tomoe Sharingan.

Back then...

Black Zetsu had thought some insignificant nobody was courting death.

But then...

That battle had nearly scared Black Zetsu to death.

Because Black Zetsu had never expected that this insignificant nobody had obtained the God Tree Remnants, mastered the power of Wood Release and Natural Energy, possessed formidable taijutsu and swordsmanship, and even had a little Slug by his side. He had beaten three-tomoe Indra so badly that Indra could not even lift his head.

Black Zetsu had been secretly following Indra all along. When it tried to help Indra, it caught Shirou Emiya's attention, causing him to abandon the assassination.

Later...

It had failed to escape.

That was how it came to know Shirou Emiya.

It also learned of Shirou Emiya's goal: he wanted to destroy the Ninja Sect founded by the Sage of Six Paths.

When the Sage of Six Paths had grown old and frail, the ideals of the Ninja Sect had gradually spread, and some disciples had left the Ninja Sect to return to their homelands.

Some Ninja Sect disciples had used Chakra to benefit the people, while greed had arisen in the hearts of others, and they had begun using Chakra to seize profit.

Shirou Emiya had been one such victim.

For the sake of several bottles of fine wine, a Ninja Sect disciple had used the power of Chakra to slaughter everyone in a village. Shirou Emiya had only survived because he had left the village beforehand.

To avenge himself upon that Ninja Sect disciple, Shirou Emiya had prayed to the remnants left behind by the God Tree, eventually gaining the power of Wood Release from the God Tree Remnants.

The power of Wood Release was indeed formidable...

But using it to challenge the Sage of Six Paths was simply a fool's dream!

Black Zetsu had not believed that Shirou Emiya, this pawn, could prove useful in any way.

Black Zetsu had barely paid any attention to Shirou Emiya. It only knew that he traveled throughout the Shinobi World saving people while spreading the ideals of Medical Ninja to everyone he met.

Back then...

Black Zetsu had been riding high.

Because Black Zetsu's first plan had succeeded. It had taken the initiative to provoke Indra into challenging Ashura, hoping Indra would seize Ashura's power and thus awaken the Rinnegan.

Yet Indra had suffered a crushing defeat at Ashura's hands.

Its first plan had failed swiftly.

Black Zetsu, once so pleased with itself, had gone into hiding in disappointment.

While it had been downcast, Shirou Emiya had continued saving people everywhere, declaring that Chakra was a force meant to free people from suffering, not a weapon used by Ninja Sect disciples to make the world suffer.

In that era...

Shirou Emiya had truly gained prestige surpassing that of the Sage of Six Paths.

Because people in that era had always worshipped the God Tree, while the Sage of Six Paths had destroyed humanity's faith.

By comparison...

Shirou Emiya, who never stopped saving people, was deeply worthy of respect, especially since he worshipped the God Tree just like everyone else.

A little Slug like a booger was always draped over Shirou Emiya's shoulder as he traveled the land, curing the world's ailments. Even the Sage of Six Paths and his son Ashura greatly admired Shirou Emiya's ideals.

Shirou Emiya had created the ideals of Medical Ninja.

Enduring pain unbearable to ordinary people, yet still striving to save those unable to escape their suffering.

Such kind ideals...

Naturally earned the admiration of that hypocrite, the Sage of Six Paths, who pretended to possess lofty morals.

Even Black Zetsu...

Had realized that Shirou Emiya was truly a kind and good man.

Of course.

Following the principle that bad people also liked good people.

Black Zetsu had greatly liked good people like Shirou Emiya, who could be exploited.

During those lonely years after its plan had failed, Black Zetsu seemed to have found a kindred spirit. Tirelessly, it spoke ill of the Sage of Six Paths in Shirou Emiya's ear, and together they condemned the Ninja Sect disciples who abused Chakra and caused destruction everywhere.

Among those conversations...

Naturally, it had revealed quite a few secrets.

For example, the Sage of Six Paths had been the source from which Chakra spread.

This had not been much of a secret in that era. Catching any Ninja Sect disciple would generally be enough to learn it, but it had aroused Shirou Emiya's curiosity about the Sage of Six Paths.

After the Sage of Six Paths died, Shirou Emiya had wanted to dissect his body. He wanted to understand the source of Chakra so that he could find a way to reclaim the Chakra that brought suffering to people through those Ninja Sect disciples.

Black Zetsu knew he was not seeking power.

As a Medical Ninja, he needed to study the organs of the human body.

Shirou Emiya had also been the first person to dissect corpses, doing so to improve his medical skills.

More than once, Shirou Emiya had told Black Zetsu that he wanted to break the world's prejudice against surgery. After his death, he wanted to turn his own body into a human specimen, so that later generations could learn medical skills from it. In the future, he had indeed done exactly that.

Black Zetsu had told him where the Sage of Six Paths' body was.

Because the Sage of Six Paths' power had been so overwhelming, Black Zetsu had not dared approach his corpse, fearing that even after death, the Sage of Six Paths might retain his might and sense its presence.

Shirou Emiya had no such reservations.

He had efficiently stolen the Sage of Six Paths' body.

To study the Sage of Six Paths' corpse, Shirou Emiya had taken it to a place abundant in Natural Energy, beginning a long period of secluded cultivation.

That place was called Shikkotsu Forest.

Shikkotsu Forest was filled with deadly acid.

Although Shirou Emiya had invited Black Zetsu to come along, Black Zetsu had not dared approach the lethal Shikkotsu Forest.

When Shirou Emiya appeared in the world once more, a gigantic Slug followed at his side. He had already acquired part of the Sage of Six Paths' power and successfully transplanted the Sage's Rinnegan.

Black Zetsu had never imagined...

That human research could achieve such results!

That time...

Before Black Zetsu could even guide Shirou Emiya on how to gather Chakra, Shirou Emiya had already acted on his own!

With a single strike, Shirou Emiya had crushed the entire Ninja Sect!

Shirou Emiya had killed countless Ninja Sect disciples and reduced Ninshu Village to ruins. He had been only one step away from destroying the Ninja Sect founded by the Sage of Six Paths!

That had been the closest Black Zetsu's plan had ever come to succeeding.

It had also been Black Zetsu's most satisfying revenge against the Sage of Six Paths!

Not only had it physically destroyed the Sage of Six Paths' Ninja Sect, it had also delivered a spiritual blow that pierced the hearts of the Ninja Sect!

But then...

Shirou Emiya had lost to Ashura.

Because Shirou Emiya had once met Ashura.

While secretly gathering and disposing of the God Tree Remnants, Shirou Emiya had encountered Ashura in a village deeply harmed by the God Tree Remnants. Ashura had been helping the villagers dig wells, and Shirou Emiya had considered him a good man as well.

In the end, under Ashura's earnest persuasion, Shirou Emiya had chosen to believe Ashura's promise. He believed that under Ashura's leadership, everyone could gain more power to save suffering people.

This man...

Had resolved to entrust his dream to Ashura.

To atone for his sins, Shirou Emiya had even used the Rinne Rebirth Technique contained within the Rinnegan, communicating between yin and yang to revive those who had died in battle.

Because the power of the Six Paths was so strong, Shirou Emiya had not died on the spot after using the Rinne Rebirth Technique. He had returned to Shikkotsu Forest to prepare for his final arrangements.

When Shirou Emiya appeared again, only a Crystal Coffin containing half a corpse remained. The Slug entrusted that Crystal Coffin to Ashura.

What a naïve man...

He had actually believed Ashura's promise...

Yet Shirou Emiya's success had also shown Black Zetsu another possibility.

Over these thousand years, throughout the long ages Black Zetsu had lived, it had worked to provoke the descendants of Indra and Ashura into fighting while also spreading the greatness of Medical Ninja, hoping someone could master human experimentation as Shirou Emiya had.

Come to think of it...

This was also why Black Zetsu often felt confused.

It was a murderer who created wars, yet it also diligently spread the sacred ideals of healing the sick and saving lives.

The reason Shirou Emiya's story had continued to be passed down in this era while the Sage of Six Paths' story had instead become legend was largely Black Zetsu's doing.

Unfortunately...

Whether through its own methods or Shirou Emiya's approach, Black Zetsu had never again seen any hope of success.

That was precisely why...

Black Zetsu missed Shirou Emiya even more.

Because among Black Zetsu's countless plans, Shirou Emiya had been the one that had come infinitely close to success.

What a pity...

If only Shirou Emiya had not believed Ashura in that era.

"Hehehehe..."

A mocking smile appeared on Black Zetsu's face.

It imagined how regretful Shirou Emiya's face would be, and how ashamed he would feel over his betrayal long ago, should they meet again!

"Now that you've seen the endlessly fighting shinobi, do you regret believing Ashura's foolish words back then?"