Wei Yuan fell into deep thought.

Causality, for some inexplicable reason, was appearing in piles upon piles. He rubbed his temples, feeling that the ripples of yin and yang he could see were becoming increasingly numerous. What he needed was a vast and sturdy causality spanning the sea of yin and yang, with Zhang Ruosu, who was originally destined to return to the future, at its core.

But now, these added causalities were all from this era.

The more entangled he became with the causality of this era, not only would Wei Yuan be more susceptible to the influence and devouring of the yin-yang ripples, dramatically increasing the number he had to resolve each day, but it would also create greater resistance to his leaving this world.

"I must further restrain my actions. Unless absolutely necessary, I should avoid contact with the people of this era. I absolutely must… otherwise, I might end up stuck in this era forever, making it even more difficult to return."

Wei Yuan looked at the layers of yin-yang ripples appearing before him, reached out his hand, and tapped his finger.

*Dang.*

Like the clear sound of a jade chime, it slowly dispersed.

In the void, another ripple of laws formed from the Qi of yin and yang dissipated, transforming into the balance of yin and yang. The black snake clinging to the old tree branch opened its mouth and exhaled dark ink-like Yin Qi, while the pure Yang Qi dispersed, flying into the turtle's body, making the patterns on its shell even more intricate.

Wei Yuan practiced in peace and resolved to avoid entangling himself in too much causality.

Each day, he merely focused on breaking the yin-yang ripples, suppressing their interference to the lowest possible level. As time passed, he found that dealing with these ripples of yin-yang laws wasn't so dull after all. After all, everything belonged to yin and yang, and there was a certain beauty in disassembling and reassembling them.

Wang Chongyang needed at least several decades to attain the Dao.

According to history, he would only take a further step after founding the Quanzhen lineage, under the feedback of the world's Qi.

During this long period, Wei Yuan had plenty of time to slowly analyze. However, as his understanding of the Dao of yin and yang gradually increased, the yin and yang Qi in this place naturally became more and more concentrated. The snake and turtle originally could not have swallowed so much vitality.

But in the beginning, Wei Yuan only released one thread each day.

The second day would be a little more, and the third day might be a little less. As time slowly passed, they also gradually became familiar with the yin and yang Qi. The snake, which was originally only the length of a palm, eventually became larger and larger as it swallowed pure Yin Qi every day, almost like a mythical beast. The turtle, without realizing it, had also grown as large as a millstone, replacing the green stone that Wei Yuan sat upon.

On weekdays, they would come here to devour vitality, occasionally listening to Wei Yuan's lectures.

And when Wei Yuan was immersed in analyzing the laws of yin and yang, they would quietly sneak down the mountain to frolic, never harming anyone, just running around in the mountains, splashing in the cold pool at the foot of the mountain, causing waves. Occasionally, when people saw them, they looked like giant beasts churning, their scales gleaming like iron. Especially at night, when the moon was bright, the giant snake's movements would create sparks as its scales rubbed together, stretching out like a god or a dragon.

Fortunately, these two had occasionally heard Wei Yuan's lectures on Daoist teachings. They swallowed the essence of the sun and moon every day, following the orthodox Daoist cultivation method, and did not harm people. It was just that their size was truly enormous, and even if they said they were very kind, everyone who saw them would be scared half to death.

Even though the two beasts had their own mysterious methods to protect the minds of those they encountered.

Those people, once they recovered, would only let out a strange cry, shouting, "Oh my heavens!" wishing their mothers had given them extra legs so they could scramble away as quickly as possible.

No one knew how much time had passed, but Wei Yuan finally gained another understanding of the Dao of yin and yang. He stretched out his finger and pointed, and saw the yin and yang Qi changing unpredictably, displaying many mysterious characteristics. When he shattered the yin-yang ripple in an instant, he swept his fingers forward.

In the next moment, the countless ripples gathered as one, like a sharp sword, cleaving the front and splitting open a crack before Wei Yuan's eyes. On the other side of the crack, he could vaguely see the surging yin-yang tribulation and his own body sitting there.

Wei Yuan murmured to himself, "So that's how it is."

"Yin and yang encompass all things, and naturally, space and time are also within their scope."

However, although he could now analyze space, it was actually because the yin-yang tribulation was constantly impacting Wei Yuan's body, which in turn affected him at this moment. Therefore, he could reverse-trace the location. After thinking about it, Wei Yuan stretched out his finger and gently tapped.

At this moment, the Xuan Black Turbid World Flag beside Wei Yuan's main body suddenly burst forth with flowing light.

Then, it unexpectedly split into a phantom image.

In an instant, Wei Yuan, who was sitting cross-legged on the old turtle's back, also had a Xuan Black Turbid World Flag in his hand. It looked exactly like the original Xuan Black Turbid World Flag, but its spiritual essence was far inferior, and there was a faint sense of ambiguity.

Such a profound magical treasure splitting into multiple shadows was only ordinary; it would be strange if it couldn't do so. Wei Yuan held the flag, verifying his guess, and gained more insights into the changes and flow of the Dao of yin and yang.

Wei Yuan shook his right hand, and the Xuan Black Turbid World Flag suddenly unfolded, displaying the divine power of the changes between purity and turbidity. The yin-yang law ripples around Wei Yuan were suppressed in an instant and were no longer so annoying. Wei Yuan breathed a sigh of relief and said, "Indeed, relying on the suppression of this magical treasure can greatly reduce the interference of the yin-yang laws."

"Next, I just need to avoid adding new causality."

"Then I can stay here relatively safely, and then when Wang Chongyang attains the Dao and the Eight Immortals cross the sea, I can return smoothly."

Wei Yuan breathed a sigh of relief, but then he saw that the old turtle was still there, but the large snake clinging to the branches of the old tree had disappeared. He looked left and right, but couldn't see it. He frowned slightly, looked at the old turtle, and asked, "You two, where did you go to play again?"

The old turtle shook its head repeatedly, then nodded, constantly gesturing in one direction.

Wei Yuan said, "Do you want me to go with you?"

When Wei Yuan got up, he realized that he had been sitting here for far too long. He didn't know how much time had passed. In addition, the yin and yang Qi flowed and dissipated everything. Even the shoes on his feet had turned to dust and disappeared. It must have been when he accidentally dismantled the yin and yang one day and affected his shoes.

When he raised his hand, he found that the wooden hairpin had also been eaten away by insects, so he simply took it off and threw it aside.

Knowing that Wei Yuan was about to move, the old turtle was very diligent, taking the initiative to stand up, generating waves of water under its feet, carrying Wei Yuan outwards. On the way, it told Wei Yuan what had happened—

There was a garrison of troops at the foot of the mountain. They didn't know which army it was. The turtle and snake didn't know that there was a garrison below, and they had gone down to wander around. Occasionally, they were seen by the fierce soldiers of the army, but they had never harmed anyone. Instead, they had helped the garrison drive away tigers and leopards. After going back and forth, those soldiers had actually built a small shrine for them.

They found someone to carve wooden statues and draw portraits.

Because it was a shrine built by humans, and because they were simply worshipping spirit beasts, they were afraid that some scholar-officials would say that it was some kind of lewd and evil worship, and spray them with abuse. Therefore, these soldiers slapped their heads and simply asked the artisans who painted portraits for the generals in the army to draw them in human form.

And because these artisans were used to painting military generals, they were too lazy to change it. They simply replaced the heads of two military generals with a turtle and a snake. The turtle held a pair of hammers, while the snake, like the reckless Zhang Fei from the Three Kingdoms era, held a spear that was a丈八 (zhàng bā, approximately 10 feet 4 inches).

The reason why the snake wasn't here today was because there was a plague at the foot of the mountain.

It received incense offerings. Although these things were of no use to it, its intelligence was like that of a child. It had already regarded those who drew portraits for it and offered it food as friends. When Wei Yuan arrived, he saw the snake high in the mountains, opening its mouth and exhaling, absorbing all the plague Qi into its mouth.

Then, it would use pure Yin to grind it to pieces.

However, doing so could only swallow the plague Qi and prevent it from continuing to spread.

It was difficult to restore the bodies of those who were already sick, and its cultivation level was not very high. Doing so reluctantly was already damaging its foundation. Wei Yuan saw from afar that the people were all pale and sickly, coughing non-stop, and he could occasionally hear cries. He sighed and said, "Come back."

The black snake, already exhausted, swam over, its scales as large as boulders.

Wei Yuan looked at the situation at the foot of the mountain and, for some reason, suddenly thought of the young Daoist he had been long ago, rushing around to treat epidemics and save lives. He chuckled self-deprecatingly and said, "I just said I didn't want to get involved in causality."

"Did you want me to break my resolution so quickly?"

He gently tapped the Xuan Black Turbid World Flag in his right hand on the ground. Suddenly, there was a commotion in the military camp below. Then, under their almost half-joking shrine, they heard several loud cracking sounds. A spring of water actually appeared, with water gurgling out of it.

A calm voice fell, saying, "Those suffering from illness can drink from this spring."

Everyone was stunned. Then, someone tried drinking the water and, sure enough, their illnesses were gone. The general then discovered what his soldiers had done and said, "You actually worship these mountain spirits?!" In order to avoid being punished, the soldiers had no choice but to stubbornly quibble, "This, this is not a mountain spirit."

"That day, we saw a giant turtle carrying a giant snake down, just like Xuanwu."

"Ah, yes, yes, yes, it's Xuanwu!"

The general frowned and said, "Xuanwu is one of the Four Symbols, just a totem, not a personified deity."

"How could it descend a miracle and even speak human language?!"

The strategist next to him saw that the general was angry and said with a smile, "Even demons can cultivate into human form, let alone divine beasts? Anyway, the people's plague has been removed, so this is a good thing. It can also be considered a merit of the general. Secondly, the Emperor has been in a bad mood recently. This matter can be regarded as an auspicious omen. If you report it to the imperial court, it can also please the Emperor."

The general's expression softened. He glared fiercely at his subordinate soldiers and slowly nodded.

"So be it…"

Only then did the soldiers breathe a sigh of relief.

*Song · Gao Cheng's "Jiwu Ji Yuan"* — In the camp, there were soldiers who saw turtles and snakes, so the soldiers built the Zhenwu Hall.

In the second year, in the intercalary fourth month, a spring surged from the side of the hall. It was inexhaustible, and those who were suffering from plague drank it and mostly recovered.

The Emperor issued an edict to build a temple, bestowing the name "Xiangyuan."

The personification of the God of Xuanwu began from this point, because of the taboo against Song Dynasty founder Zhao Kuangyin's courtesy name, Xuanlang.

Therefore, it was not called Xuanwu.

It was renamed Zhenwu.

After this matter was settled, the emperor heard of the traces of an immortal and sent a Daoist priest up the mountain, hoping to use the art of Qi observation to pay respects to the true face of this Zhenwu immortal, so as to sculpt an image for worship. And just as this happened, Wei Yuan sat cross-legged in the mountain, looking at the almost frantically rising causality around him, the corners of his mouth twitching, bewildered.

"That's not right…"

"This isn't right, is it??"

"I did save people, but can curing them bring so much causality? So much?!"

"Damn it, are you messing with me?!"

ps: Second update today

"Jiwu Ji Yuan" is a book from the era of Emperor Zhenzong of Song, but it has been moved forward here.