Fang Yuan was not oblivious to this upcoming battle going on down below. The Shen tribe, like all empires, wished to expand and unite the Fang Yuan Continent under a single sword.
While this total subjugation offered a slight upside for Fang Yuan - as it would finally establish a proper societal structure across his continent - it came with a major drawback. The Shen tribe fiercely opposed the use of Gu worms, which ran directly counter to Fang Yuan's goal of fostering a thriving Gu Master culture among the continent's inhabitants.
Arrayed against this empire was Wang Tian and his ragtag coalition. Observing from above, Fang Yuan could see at a glance that they were destined to lose miserably, unless Wang Tian could somehow pull off a miracle using his gu worms or stumble into an extraordinary stroke of fortune.
For his part, Fang Yuan remained detached from their struggle, focusing his efforts on elevating his mortal killer move, Ambition Triumphing Over Heaven, into a true immortal killer move. His patience and refrain from interfering finally paid off.
Within his Integration Formation, a large chunk of truthful floating ice coalesced.
Upon devouring the ice, complex insights into the Human Path flooded his mind. His human path attainment was already at the quasi-Great Grandmaster level, and even after consuming this block, it remained there.
The reason was unique: although Fang Yuan's comprehension of the Human Path had vastly deepened, the total depth of the path itself had expanded alongside his discoveries. It was the equivalent of pouring water into a bucket while the bucket simultaneously grew larger; the relative proportion of water within stayed the same even if there was more water there.
However, his innovations had a hidden, devastating effect on the wider world. If there were any other Human Path Gu Immortals in existence, their own attainment levels would have actively dropped, going from Great Grandmaster to simply Grandmaster, or Grandmaster to simply Master, because Fang Yuan had greatly shifted the boundaries and scope of the path itself.
***
Down below on the Fang Yuan continent, Wang Tian was anxiously attempting to refine a Gu worm in secret.
"I hope Bai Xiao doesn't see me like this," he muttered to himself.
If they wanted to stand a chance against the overwhelming numbers of the Shen tribe, they needed raw firepower. Having observed certain gu worms interacting in the wild, Wang Tian had gained the inspiration to refine something new himself. He kindled a small blaze and began tossing primeval stones into the mixture.
Right at the critical moment, a commotion erupted outside. Startled by the noise, a wild gu worm flew directly into his refinement cauldron.
'Oh no! Who knows what's going to happen now?' he thought in a panic.
The stray intruder was a black-and-white rotating disc - a wild Yin-Yang Rotation Gu. Wang Tian instinctively thought about aborting the process, but his Vital Gu was already fused deep within the volatile mixture. He didn't know that a Vital Gu is never destroyed during a refinement failure so long as basic protocols are maintained, so the sheer terror nearly triggered a severe mental backlash.
Refusing to give up, he stabilized his focus and spat a mouthful of blood from the backlash but began focusing once again.
To his utter shock, the refinement did not detonate.
Instead, the cauldron erupted in a brilliant light. When the smoke cleared, his Vital Gu had transformed entirely, radiating a potent Rank 4 aura!
It took the shape of two massive centipedes one stark white, one pitch black - coiled tightly around each other in a perpetual loop. The black one had a small white spot atop its head, while the white one had a small black spot atop its head.
Watching closely from his aperture's White Heaven, Fang Yuan was genuinely surprised. Wang Tian had inadvertently created a brand new species of gu worm that even Fang Yuan did not recognize. It was a discovery born of pure chance, and Fang Yuan immediately memorized the process to exploit it later.
Wang Tian, however, stared at the strange twin-centipede Gu in dismay, completely ignorant of its properties and assuming his refinement had simply gone horribly wrong.
Later that night, as Wang Tian was preparing for sleep, Shen He visited his quarters.
"Shen He, do you still intend to stay for the battle?" he asked softly. "You can run away, you know. No one would blame you."
Shen He shook her head firmly. "When it is my own tribe causing you such ruin, how could I abandon you? Especially when... when you are dying."
Wang Tian froze. "How... how did you know?"
"I've noticed a change in your demeanor lately," she said, stepping closer. "You carry yourself like someone who is walking to their grave, and not simply because of the war ahead. What is the cause? Do you have an incurable disease?"
Wang Tian sighed and shook his head. "No. It is the Verdant Sun Great Yang physique. Doctor Gu explained it to me. Even though I have advanced in rank, the extreme physique is still manifesting. Soon enough, the pressure will cause my aperture to self-detonate."
Realization dawned on Shen He, and the reason as to why Wang Tian had kept this secret hidden from her. "That means... since I share a similar physique, I am going to eventually die too?"
"I'm sorry," Wang Tian said. "But Doctor Gu has no cure for it. I don't even know if a cure exists in this world."
Much like Verdant Great Sun and Ancient Desolate Moon in The Legends of Ren Zu, the two of them were destined to meet an early grave.
"In that case," Shen He said, stepping closer, "if we don't know what tomorrow brings, let us at least make full use of today."
Without another word, she disrobed.
Wang Tian was startled, his mind flashing back to the day they first met by the pond and when he had spotted her bathing.
Truth be told, his mind oftentimes wandered back to that time whenever he felt like cheering himself up, even though he would never admit it! He couldn't - what would Shen He think? That was what kept him in line.
But here she was, offering him the same sight again willingly!
"I'm sure you enjoyed watching me bathe back then," she murmured with a soft smile. "Would you like an even closer look now?"
That night, the two shared a passionate, steamy encounter.
When Wang Tian awoke the next morning, he felt an astonishing change. The agonizing, bursting pressure within his aperture had completely vanished. He hurriedly summoned Doctor Gu, who inspected him in absolute disbelief.
"It appears the volatile effects of your extreme physique have been heavily suppressed, Young Master!"
***
Fang Yuan, who was tracking these events in detail through hidden investigative Gu, analyzed the phenomenon and immediately deduced the mechanics behind it using his quasi-Great Grandmaster Human Path attainment.
By utilizing his background knowledge, he realized that the accidental refinement from earlier had combined the properties of a Yin-Yang Rotation Gu and a Unity Gu to create a brand-new entity: the Yin-Yang Unity Gu!
Much like Equality Gu, this new worm allowed the transference of dao marks between two people, specifically operating through the dual cultivation of a man and a woman.
But this naturally still led to a big question. Were that the case... then Shen He should've gotten half of the Verdant Sun Great Yang Physique and Wang Tian a portion of the Ancient Moon Desolate Yin Physique.
On the surface, this shouldn't have changed much at all as both of them would still be suffering from the effects of a unified, single, overwhelming extreme physique.
So why this kind of result?
...
Fang Yuan had a few theories as he examined the surrounding areas.
In standard mathematics, two positives stay positive, but multiplying two negatives also yields a positive. Because the Yin-Yang Unity Gu acted upon two individuals who both suffered from extreme, volatile physiques, the competing negative overloads did not worsen each other's condition. Instead, the conflicting chaotic energies perfectly counterbalanced, canceling each other out and safely venting the excess pressure into the air as pure Yin-Yang aura. Both of these energies were nearly equivalent, and so canceled each other out and didn't result in any kind of abnormal phenomenon.
Fang Yuan knew little of the Yin-Yang Path or whether or not it could even be called a proper path in and of itself, but if it was a path, it could be seen as a branch of the Human Path.