While the player is in Battle Through the Heavens, the system is in The Great Ruler.

Chapter 30 The Wonders of the Emperor's Scripture, Ascetic Cultivation Underground

"The Great Emperor's Inner Classic, isn't this the dual cultivation technique of the Western Heaven War Emperor that is famous throughout the Great Thousand Worlds?"

Lu Yu raised an eyebrow, looking at the three options in the simulation with some surprise.

As the strongest being below the Saint-grade Heavenly Supreme in the Great Thousand World, the Western Heavenly War Emperor has cultivated his cultivation to the extreme of the Immortal-grade Heavenly Supreme, and he is famous for his two major techniques.

One is called the Great Emperor's Inner Classic, and the other is called the Battle Emperor's Manual.

The Great Emperor's Inner Scripture is a unique dual cultivation method of the Western Heaven War Emperor, which is in harmony with the Great Dao of Yin and Yang. It is said that the War Emperor had three thousand concubines in his palace and rose rapidly to the position of Heavenly Supreme by means of this method.

The Battle Emperor's Technique is a unique skill inherited from the ancient Battle Emperor. It can fuse spiritual power and battle intent, transforming them into battle spiritual power, which is far more powerful than ordinary spiritual power. This technique played an indispensable role in enabling the Western Heaven Battle Emperor to earn the formidable reputation of "Emperor of a Hundred Battles".

"Of these three options, the Foundation Building Chapter of the Great Emperor's Inner Classic is the most valuable. Although it only contains cultivation methods below the Supreme Realm, its value far exceeds the other two."

"The Xuan Shui Jade is merely a mid-grade spiritual artifact. Judging from the simulation, it should contain the essence of a Fusion Heaven Realm spiritual beast. Even when fully activated, its power is only comparable to that of a Dou Huang expert."

"As for the Heavenly River Blood Blade, it is a high-level Earth-rank blood-attribute combat skill, slightly more valuable than the Profound Water Jade, but it doesn't match my attributes and is of little use to my cultivation in reality..."

"Moreover, spiritual artifacts and cultivation techniques are easier to obtain, and there will be another chance to get them in the next simulation. But the 'Great Emperor's Inner Scripture' is something that can only be encountered by chance..."

With this thought in mind, Lu Yu immediately chose the third option.

In an instant, golden light shone brightly in the void, and a gilded page appeared out of thin air, illuminating the entire quiet room with its radiant glow.

Lu Yu held his breath and saw that the golden page was densely engraved with ancient runes. He carefully reached out and touched it, and the golden page immediately turned into a stream of light and disappeared into his brow.

In an instant, a deluge of information exploded in my mind—

"When yin and yang are in harmony, heaven and earth unite in balance..."

"Gathering the essence of heaven, absorbing the radiance of the moon..."

"The cycle of Yin and Yang, the creation of nature..."

The contents of the Great Emperor's Inner Classic flowed through his mind like a clear spring, and the profound mysteries of dual cultivation contained within it appeared one by one in his mind.

After a while,

Lu Yu slowly opened his eyes, a sharp glint in them. He thoughtfully touched his brow, inwardly shocked: "So that's how it is. This technique uses heaven and earth as a furnace, the sun and moon as fuel, transforming the two Daoist partners into spiritual embryos of heaven and earth. It borrows the power of heaven and earth, transforming the essence of the sun and moon into yin and yang energies to nourish their foundations..."

He focused intently on comprehending the true meaning of the technique, and the more he comprehended it, the more astonished he became: "The most exquisite aspect of this technique lies in its ability to regard the two people cultivating together as a perfectly formed Yin-Yang spiritual embryo. Through the Yin and Yang energies transformed within the body, any injury can be healed—even if the meridians are completely severed or the dantian is damaged, as long as a wisp of Yin and Yang energy remains, it can be completely repaired!"

"Everyone says that the Western Heaven War Emperor is a romantic and unrestrained man..."

A glint of light flashed in Lu Yu's eyes as he muttered to himself, "It seems that this person is actually a peerless genius who has comprehended the Great Dao of Yin and Yang!"

"Using heaven and earth as a furnace and the sun and moon as firewood, the way of men and women is pushed to a realm of unparalleled perfection. Such methods are far beyond ordinary techniques of sexual cultivation; they are clearly the great principles of emulating heaven and earth and learning from nature!"

Thinking of this, Lu Yu couldn't help but sigh, "Indeed, every powerful individual in the Great Thousand World who can achieve the Heavenly Supreme realm is no ordinary person. The Western Heaven Battle Emperor was able to reach the Heavenly Supreme realm through dual cultivation; regardless of his character, his comprehension is truly admirable..."

……

Soon after,

Somewhere underground in the eastern Tagor Desert.

In the fiery underground magma world, crimson lava surges like raging waves.

"boom!"

A crimson serpent shadow slammed heavily against the rock wall, the two-headed fire spirit serpent letting out a painful hiss. Hai Bodong stood in mid-air, his icy blue battle aura flowing around him, freezing the surrounding magma into ice crystals. "Little girl, now's the time!" Hai Bodong turned and shouted.

Qinglin nodded nervously. After this period of training, she had become proficient in using the Azure Serpent Three-Flower Pupil. Although she had not yet reached the point of being able to use it at will, she was already somewhat confident in facing the two-headed fire spirit serpent in front of her.

She formed a hand seal, and three small flowers slowly rotated in her emerald eyes, releasing a peculiar energy wave: "Azure Serpent Three-Flower Pupil, open!"

In an instant, the massive body of the two-headed fire spirit serpent trembled violently, and the emerald green three-flower mark was simultaneously reflected in its four scarlet snake eyes, as if it had been branded.

After a while,

As the two eerie emerald flowers fully formed on the snake's head, the three small flowers in Qinglin's eyes receded like a tide, instantly returning to their original clear emerald green. She swayed, her face as pale as paper, clearly exhausted.

"It...it's a success..." Qinglin smiled weakly.

Lu Yu reacted swiftly, appearing beside her in a flash and taking out a smooth, jade-like pill from his storage ring: "Quickly take this Soul Nourishing Pill!"

He carefully fed the pill to Qinglin, while simultaneously circulating his battle qi to help her neutralize its effects. Qinglin's pale face gradually regained its color, and the weariness between her brows slowly faded.

"Thank you, young master..." Qinglin said softly, her eyes filled with gratitude.

Lu Yu gently instructed, "During this time, you should focus on recuperating and establishing a connection with the Fire Spirit Serpent. Don't worry about other trivial matters."

"Qinglin understands," the girl replied obediently.

Lu Yu turned to the little fairy doctor who was standing quietly to the side: "Fairy, I'll trouble you to take her back to Stone Desert City first."

The girl in white nodded in understanding, and with a gentle lift of her delicate hand, she naturally took Qinglin's arm.

After the two of them left,
Lu Yu looked at Hai Bodong and said with a smile, "Old Hai, let's begin."

Hai Bodong raised his white eyebrows slightly, and with a light wave of his sleeve, countless ice crystal blades suddenly condensed.

"Watch out, little brat!"

Before the words were even finished, hundreds of cold glints of light pierced the air and arrived.

shhhhhh!
The piercing sound of wind cutting through the lava cave echoed. Lu Yu lightly touched the ground with his toes, his figure retreating rapidly like a dragon, leaving several afterimages in his wake. Seeing the ice blades approaching, he suddenly clasped his hands together, and the crimson afterimages exploded, transforming into a ring-shaped shockwave that shattered all the incoming ice blades.

"Hmph, you're quite willing to squander your battle qi in this lava field."

Hai Bodong snorted coldly, but a hint of approval flashed in his eyes. He said in a deep voice, "However, do you think you can avoid it like this?"

A sudden sense of alarm arose in Lu Yu's heart. Before he could react, the magma beneath his feet suddenly exploded—countless sharp ice spikes shot out from the scorching lava!
"what?!"

Lu Yu hastily dodged, but was still ripped through his sleeve by an ice spike. The icy chill seeped in through the tear, instantly causing a thin layer of frost to form on his right arm.

Hai Bodong stood with his hands behind his back, his white hair flying in the air: "Boy, this old man will not show any mercy!"

Having said that, he swiftly formed a profound hand seal with his palms. In an instant—

shhhhhh!
Thousands of ice crystal blades materialized out of thin air, each gleaming with a cold, eerie blue light, and poured down like a torrential rain.

Rumble!
At the same time, the ground trembled violently, and sharp ice spikes pierced through the scalding magma, striking from incredible angles. Amidst the interplay of ice and fire, the entire cave was shrouded in billowing white mist.

Looking at the overwhelming offensive, Lu Yu gave a helpless, bitter smile. The days ahead were probably going to be tough…

(End of this chapter)