Chapter 177

Zhang Shijie, being a composed person, let some emotion flicker across her face before it vanished; she merely shook her head and said to Zheng Fa and the others:

"This Xuanguan Mirror is an artifact from my master's youth; only one who has formed a Nascent Soul may leave it."

"Nascent Soul…" Zhang Shijie blurted out: "Nascent Soul is so hard to achieve…"

Seeing Zhang Shijie fall silent, she realized she had spoken wrongly and added quickly:

"Luckily, Master Zhang, your talent is extraordinary! What's difficult for others won't be hard for you!"

"No, I find it even harder than others," Zhang Shijie said softly. "In my early years, I cultivated too quickly—now I must pay the price."

Even Zheng Fa couldn't help but nod at this.

He had heard of Zhang Shijie's history:

Normally, a single-element cultivator needs two or three years to reach Foundation Establishment, but Zhang Shijie achieved it in less than a year.

When she formed her Golden Core, she had only been cultivating for a decade.

Her fame surged, and she was regarded as the top cultivator under Nascent Soul in the Hundred Immortal Alliance.

Yet for the past eighty or ninety years, she had been stuck at the Golden Core realm, making no progress.

She sealed herself inside the Xuanguan Mirror, escaping the Nascent Soul cultivators of the Great Freedom Demon Sect—but also trapping herself in a dire situation: she could not leave unless she achieved Nascent Soul.

"Zheng Fa, remember this… Foundation Establishment must be approached with caution," Zhang Shijie advised, despite her own plight. "I had no experience back then; I walked a path no one had taken before. Many things I didn't understand—I was young, blinded by the title of 'Number One Genius of the Hundred Immortal Alliance.'"

"Later, when I realized my Fu Dao Foundation Establishment method was incomplete, I checked ancient texts and learned that if one truly creates a complete Dao path, heaven and earth will manifest signs."

"... igns?"

Zheng Fa found this hard to understand.

"Few know this," Zhang Shijie explained. "Spiritual energy has declined at least five times; no one knows the origins of cultivation methods—they may have been perfected before the last great calamity. Thus, those who create new Dao paths are exceedingly rare. In these two calamities, only one person truly invented a new cultivation method—"

Zheng Fa twitched his lips.

He already guessed who it was.

"Ancient texts record that the Heaven River Master, after forming his Golden Core, created the method of the Numinous Treasure of the Primordial Self—now the foremost path to Nascent Soul in the Xuanwei Realm. At that time, the Dao itself responded: signs appeared across the entire Xuanwei Realm. The Heaven River Master then said, 'When a Dao path is born, signs appear.'"

Of course—you're everywhere, Heaven River Master!

"When I condensed my Foundation using the Fu Dao Foundation Establishment method, no signs appeared—perhaps because it was merely a Foundation Establishment technique."

"But it's also possible," Zhang Shijie sighed softly, "that the Yuanfu Dao I formed was flawed, and thus not a complete Dao path. I only realize this now."

"Cultivation is one misstep leading to endless errors," Zhang Shijie continued advising Zheng Fa. "I still haven't found a way to form a Nascent Soul. Even if I did, future difficulties may arise—Zheng Fa, if you don't want to end up like me, be thrice cautious in Foundation Establishment."

Seeing that even now, she was still advising him,

Zheng Fa interrupted: "Sister Zhang, do you have confidence in forming a Nascent Soul?"

"..." Zhang Shijie fell silent for a moment. "Golden Core cultivators live a thousand years. I still have nine hundred years. No rush."

"..."

This sounded confident.

In truth, it was utterly lacking in confidence.

In the Xuanwei Realm, Qi Refining cultivators live barely longer than ordinary people—around a hundred years.

After Foundation Establishment, one lives to three hundred.

Golden Core: a thousand years.

Nascent Soul is a great leap—rumor says the Sect Master is already around ten thousand years old.

But... these are ideal lifespans.

As Zheng Fa knew, very few cultivators die of old age.

Zhang Shijie survives only because of Lei Chi. Now that the Heavenly Stele has appeared, Lei Chi may change. The Great Freedom Demon Sect looms nearby—if Lei Chi can no longer protect her, can she even survive another nine hundred years?

Even if she survives—her flawed Golden Core cannot be fixed by time alone.

With Zhang Shijie's nature, if she truly had confidence, she wouldn't answer so evasively.

"Sister Zhang, I have a hypothesis about Yin-Yang Yuanfu..."

At this point, he could only hope the Yin-Yang Yuanfu might spark some insight for her.

Zhang Shijie's spirits lifted slightly; her face brightened with anticipation as she listened closely to Zheng Fa's explanation.

"Handedness?"

"Mirror image?"

After Zheng Fa finished, Zhang Shijie closed her eyes, as if simulating within her body.

After a long while, she nodded slightly, then shook her head, her expression calm yet tinged with disappointment.

"I understand handedness," Zhang Shijie told Zheng Fa. "The Yin-Yang Fu diagram does correspond to the right and left hands."

"But mirror image... is inaccurate."

Zheng Fa nodded slightly—he had realized this himself:

"Only among the Five Element sub-symbols do the Yin-Yang diagrams mirror each other. But the Fu diagram consists of three sub-symbols."

"The other two types of sub-symbols differ in the Yin and Yang diagrams—they cannot be considered mirror images."

For example, in Zheng Fa's Yuanfu, the Yin Earth sub-symbol is the Upright Shadowless Talisman, while the Yang Earth sub-symbol is the Awakening Spirit Talisman.

The only identical structure between them is the Earth sub-symbol.

The other two sub-symbols are entirely different.

Calling them mirror images is a stretch.

Zhang Shijie nodded slightly. Seeing Zheng Fa's slightly downcast expression, she suddenly smiled: "The mirror image idea isn't necessarily wrong."

"Hmm, it just didn't help you, Sister Zhang."

Zheng Fa murmured.

Last time, after he proposed the Five Element sub-symbol theory, Zhang Shijie had made progress.

Now, it seemed she gained no insight.

"No, you've done well," Zhang Shijie suddenly said. "Zheng Fa, do you know what I thought of when I sealed myself inside the Xuanguan Mirror?"

"What?"

"Relief," Zhang Shijie said softly. "Relief that I went to Zhao Fu that time."

"Relief that I brought you into Jiushan Sect."

"Relief that I passed the Fu Dao Foundation Establishment method to you."

Zheng Fa froze as Zhang Shijie continued:

"So I met you. So Jiushan Sect has its ideal future Sect Master. So the Fu Dao Foundation Establishment method has its perfect heir."

Today, Zhang Shijie spoke more than ever.

Zheng Fa felt a tightness in his chest, yet didn't know what to say.

"Zheng Fa—even the Heaven River Master perished, his spirit extinguished. How could I escape? But if you one day truly perfect the Fu Dao Foundation Establishment method, the world will know—once, in the Xuanwei Realm, there was a Zhang Wuyi," Zhang Shijie whispered.

"Lei Chi is dangerous. You two should return," Zhang Shijie said softly, seeing their silence. "I'm safe here in the Xuanguan Mirror for now. Zheng Fa, go see the Heavenly Stele instead—no need to come daily."

"Besides, I need to cultivate."

As she spoke, her expression was unusually calm.

Hearing this, Zheng Fa and the others exchanged glances and took their leave.

The next day.

Zhang Shijie sat in meditation beneath the Xuanguan Mirror, and from afar, she again saw Zheng Fa and Yuan Shijie approaching.

"Didn't I tell you two to come less often?"

A faint smile flickered at Zhang Shijie's lips as she asked.

"I just came to keep you company!" Yuan Shijie said sweetly. "Besides, I don't cultivate Thunder Dao—what does the Heavenly Stele have to do with me?"

Yuan Shijie had always been simple-minded—perhaps because of that, her cultivation progressed swiftly.

Zhang Shijie shook her head and turned to Zheng Fa.

Zheng Fa pulled several thick books from his storage pouch.

The covers bore titles Zhang Shijie couldn't understand.

"High School Mathematics Volume," "Mathematical Analysis," "Topology"...

Seeing her puzzled look, Zheng Fa said: "Sister Zhang, these are research methods possibly related to Fu diagrams. I thought they might help you."

Topology would be most helpful for studying Fu diagrams.

But topology itself requires foundational knowledge.

For instance, basic point-set topology demands a grasp of mathematical analysis—though mathematical analysis is an introductory university course, seemingly requiring no prior knowledge,

it actually requires understanding basic function theory and set theory.

Zheng Fa's "High School Mathematics Volume" covers these prerequisite concepts.

Zhang Shijie's eyes brightened; a smile appeared on her face.

"Similar to your previous secret methods?"

"These are more fundamental," Zheng Fa opened the book. "The earlier ones were just methods. These are the foundations from which those methods arise."

Zhang Shijie nodded softly, her expression eager.

Even Yuan Shijie leaned in, curious.

"First, we must understand the classification of numbers..."

Zheng Fa opened the book and began explaining slowly.

Two hours later, Zheng Fa had just entered the high school function section—Yuan Shijie could no longer endure it.

She gazed blankly at Zheng Fa's lips moving open and closed, her face slowly filling with resistance, as if her brain had activated a self-protective instinct.

"I…" she suddenly said, "I'll go take a look at the Heavenly Stele!"

"…"

Zheng Fa turned to look at her; she whispered, "I suddenly feel a connection—this Heavenly Stele is destined for me!"

"Aren't you the one who said you don't cultivate Thunder Art?" Zheng Fa asked.

"Who can say what heavenly and human resonance truly means?" Yuan Shijie called out as she ran off, "Zhang Shijie, wait until Zheng Shidi finishes explaining, then I'll come back to you!"

Watching her flee, Zheng Fa and Zhang Shijie exchanged a glance and couldn't help shaking their heads with a light laugh.

"Yuan Shimei truly lacks aptitude for this—keep going!"

Zhang Shijie's eyes sparkled brightly, as if Zheng Fa's explanations didn't overwhelm her but instead filled her with unusual fascination.

"Alright, let's first examine several basic functions…"

One spoke, one listened.

After all, they were cultivators; once fully absorbed, they forgot the passage of time.

Zheng Fa finished explaining *High School Mathematics* and moved on to the second half of *Mathematical Analysis*.

He became somewhat entranced—he had studied this before under Old White, but this was the first time he tried to articulate and teach these concepts himself.

He gained some new insights.

"Zheng Shidi?" Zhang Shijie suddenly said.

"Hmm?"

"Aren't you going to take a look at the Heavenly Stele too?"

"... uh?"

"I suddenly feel a connection—this Heavenly Stele is destined for you," Zhang Shijie said, pinching her temple as if she had a headache, yet her expression was utterly sincere.

Me? Destined for that thing? And you feel it?

This excuse sounded even more absurd than Yuan Shijie's flight.

Looking at Zhang Shijie's fearful gaze fixed on the book in his hands, Zheng Fa understood:

The transmission of this knowledge must be limited—moderation is essential.

Zhang Shijie, for instance, had already been filled to capacity…