After settling Ye Guyi in, Gu Yuejin turned and headed straight for the library of Sun Moon Royal Soul Engineer Academy.
With the black token Jing Hongchen had given him, he passed through without hindrance and went directly to the deepest, innermost section of the library.
There was none of the outside world's clamor here. The air carried a mixed scent of aged paper and specially formulated preservative ink.
Enormous bookshelves soared overhead, crammed with countless precious classics, blueprints, and cutting-edge theoretical manuscripts.
For ordinary students in the Soul Engineer Department, this was both a holy place and a living hell.
The books here were simply too obscure and too dull.
But Gu Yuejin felt right at home.
"Microscopic Structural Analysis of Soul Power Conduction Media, Topological Application of Core Magic Arrays, Critical Point of High-Energy Compression Arrays..."
Gu Yuejin ran his fingers along the rows of spines, his eyes shining with a thirst for knowledge.
Although he had a system and a heaven-defying martial soul, he had always kept a clear head—cheats were cheats, and knowledge was knowledge.
If he wanted to create an ultimate weapon capable of killing gods, brute force alone wouldn't cut it. He had to build from the ground up, starting with the most fundamental principles.
He pulled out a weighty old book with a worn cover—An Investigation into the Stability of Linked Soul Tool Arrays.
He sat down in a corner. With his vast Spiritual Power, he read at incredible speed, nearly ten lines at a glance. But that didn't mean he was skimming. His mind, comparable to a supercomputer, broke down, rearranged, and simulated every formula and theory in the book.
Just as he was absorbed in working through a complex linked circuit—
"Oh? Someone's actually reading this?"
A voice filled with surprise and curiosity suddenly sounded beside him.
"Don't young people these days all rush off to look for ready-made blueprints for Level Seven and Level Eight Fixed Soul Tool Cannons? Anyone willing to sit down and chew through dry theory like this is rarer than a giant panda."
Gu Yuejin frowned slightly. The interruption had annoyed him.
He looked up and turned toward the voice.
A middle-aged man stood by the bookshelf, watching him with interest.
The man looked to be around forty, of average build, wearing a somewhat rumpled white research coat. A few specks of some unknown metal dust clung to it.
His hair was as messy as a bird's nest, and thick black-rimmed glasses sat on his nose. His whole appearance was unkempt and disheveled.
Yet beneath that scruffy exterior, his eyes—hidden behind the lenses—were astonishingly sharp. Like a pair of scalpels, they seemed able to peel away the surface of anything and expose its core.
Gu Yuejin's heart stirred as he immediately recognized the man.
Xuan Ziwen.
The purest "Research Maniac" at Sun Moon Royal Soul Engineer Academy—or even in all of Mingde Hall.
He cared nothing for power or status, and not even for which country he belonged to. His entire life was devoted to pursuing the pinnacle of Soul Tool Technology.
In the original course of events, he would join the Tang Sect, become half a teacher to Huo Yuhao, and propel Soul Tool Technology across Douluo Continent to new heights.
"So you're the famous Teacher Xuan."
Gu Yuejin closed the book and smiled politely, showing no trace of contempt for the man's disheveled appearance.
"What, are you interested in these old theories from decades ago too, Teacher Xuan?"
Xuan Ziwen pushed up his glasses. He didn't seem surprised that Gu Yuejin had recognized him. He was something of a celebrity at the academy, after all—though mostly for his "eccentric temper" and "lack of social grace."
"I wouldn't say I'm interested. The theories in this book are basic, but many of its ideas were too far ahead of their time—even downright fanciful. That's why it was left to gather dust in a corner."
Xuan Ziwen sat down across from Gu Yuejin. His gaze swept over the book's cover, and his tone took on a hint of scrutiny.
"For instance, the problem of 'energy resonance and dissipation between multiple Core Formations' mentioned in Chapter Three. The author thought it could be solved by adding return circuits, but that would greatly increase the array's size and the difficulty of engraving it. Hardly worth the effort."
"What do you think?"
Faced with the Soul Tool master's sudden question, Gu Yuejin didn't panic.
He lightly tapped the book with his fingers. In his mind, knowledge of parallel circuits and energy feedback from his previous life surfaced, which he combined with the Soul Tool theories of this world.
"Return circuits are certainly clumsy."
Gu Yuejin spoke in a calm, assured tone.
"The author got caught up in the idea of 'blocking' the problem. If energy is dissipating, why insist on forcing it back?"
"What if we treat the dissipation as a kind of 'signal'?"
"Outside the main array, we could construct a tiny secondary sensing array that relies on the dissipated energy. We could use that energy to activate the secondary array, then use it in turn to calibrate the frequency of the main array."
"This is called—Negative Feedback Regulation."
"It wouldn't eliminate the dissipation entirely, but it could turn unstable oscillations into a self-correcting force, improving stability by at least thirty percent."
Silence.
Xuan Ziwen froze.
He had only asked offhandedly, wanting to see if this unfamiliar face was putting on an act.
But that answer...
"Negative feedback... self-correction..."
Xuan Ziwen murmured to himself. His eyes grew brighter and brighter until he suddenly pulled a pen from his pocket and began sketching rapidly on the table.
"Brilliant! Brilliant!"
"No need to add extra energy. Instead, turn waste into something useful and use the exhaust to drive the valve... What an ingenious idea!"
"Though it requires extremely precise engraving, it's completely viable in theory!"
A moment later, Xuan Ziwen jerked his head up. His eyes blazed with fervor as he stared intently at Gu Yuejin, as if he were looking at an uncut, priceless gem.
"What's your name, kid? Which class are you in? Who's your mentor?"
"An idea like that couldn't have come from those old fossils who only know how to parrot textbooks!"
"Gu Yuejin."
Gu Yuejin smiled faintly, without revealing that he was the newly appointed Department Director. "You could say I'm... self-taught."
"Self-taught?!"
Xuan Ziwen was even more astonished, then scarcely able to hide his delight.
"Good! Very good! Self-taught!"
"Your foundations seem a little unconventional, but your mind is exceptionally sharp. That kind of unconventional creativity is exactly what those students who do nothing but cram are missing!"
Xuan Ziwen stood up, dusted himself off, and extended a hand to Gu Yuejin. His voice held a rare note of sincerity and invitation.
"My name is Xuan Ziwen, one of the Chief Researchers at Mingde Hall."
"I'm very interested in you."
"If you have time, feel free to visit my private laboratory. I have some things there you won't find anywhere else. You might like them."
"Of course, if there's anything in theory you can't figure out, you can come to me as well."
Gu Yuejin looked at the hand extended toward him.
"It would be an honor."
Gu Yuejin reached out and firmly shook hands with this future master of Soul Tools.
"As it happens, I'm also very interested in the subject Teacher Xuan is researching..."
Before you continue