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

Chapter 172 The Scheme of Different Flames, Each Making Their Own Choice
"Brother Lu."

Xiao Yan's eyes burned brightly, his fighting spirit surging and soaring as he shouted loudly, "You underestimate me! I am no longer the person I used to be!"

Before he finished speaking, he twisted his body with the power of the earthy yellow vortex, narrowly avoiding the last wave of sharp, icy sword energy at an extremely tricky angle.

At the same time, the Xuanzhong Ruler in his hand suddenly trembled, and the earth-yellow Wind Fury Dragon Flame and the black and white Yin-Yang Twin Flames suddenly rose up. It was not a simple attachment, but a rapid fusion in a mysterious way!
The three-colored flames on the ruler's body swirled and compressed wildly, eventually transforming into a strange three-colored ruler beam containing violent wind pressure and the intertwining of life and destruction. With a terrifying power that could tear everything apart, it slashed heavily down at Lu Yu!

"What a trick!"

Lu Yu laughed loudly, and with a sudden flick of his wrist, the longsword made of ice soul flames emitted a clear and melodious sword cry, and the sword's momentum suddenly changed!
"Be careful, Brother Yan! Try my first level of the Yin-Yang Returning Origin Sword Technique—Dragon Coiling Serpent!"

In an instant, the sword energy on the icy blue longsword surged, but it was not simply fierce. As the sword light flowed, it contained two completely different sword energies at the same time: one was as domineering and fierce as an ice dragon, coiled and guarding, with an unwavering and steady presence;
The other was as cunning and unpredictable as an extremely cold serpent, waiting for its chance to strike, exuding a chilling aura that could kill with a single blow.

One dragon and one snake, one hard and one soft, complement each other and blend perfectly. This is the essence of the first level of the Yin-Yang Returning to Origin Sword Technique: Yin and Yang are initially separated, and the dragon and snake rise together, combining offense and defense!
The icy dragon and the phantom of the spirit serpent suddenly merged, transforming into a sharp and unparalleled pale blue stream of light, directly meeting the roaring tri-colored ruler of light!
boom!
The two powerful energies collided violently, producing a deafening roar. The energy ripples spread outwards, pressing down all the plants and trees in the courtyard.

Xiao Yan was pushed back half a step by the recoil, but his eyes burned with an even more intense flame. He took a deep breath, clasped his hands together, and three different flames suddenly emerged—the earth-yellow Wind Fury Dragon Flame, the black and white Yin-Yang Twin Flames, and the crimson and violent Earth Core Flame, as red as boiling magma!

The three-colored flames spun and compressed wildly in his palm, merging in an almost frenzied manner, and finally transforming into a slowly rotating three-colored fire lotus that exuded an aura of destruction!
"Go!" Xiao Yan shouted, forcefully pushing the Fire Lotus forward.

Faced with this fire lotus containing terrifying energy, Lu Yu's expression also became solemn.

"Good lad, peak mortal realm soul power, looks like you've had quite a few fortuitous encounters..."

He said in a deep voice, and the sword technique in his hand changed again, with the icy cold flame and a touch of blue earth core flame rising up at the same time.

Although the Earth Core Flame shares the same origin as Xiao Yan's Crimson Earth Core Flame, it exhibits a completely different azure jade color due to having absorbed the Azure Lotus Earth Core Flame.

"The second level of the Yin-Yang Returning to Origin Sword Technique—the Yin-Yang Realm!"

Two flames intertwined and swirled, and a sword aura, half blue and half green, suddenly took shape. The sword aura slowly rotated, and the power of ice and fire circulated endlessly, carrying the profound meaning of dividing yin and yang, and precisely slashed at the three-colored fire lotus!
A second, violent explosion erupted in the courtyard, the blinding light making it impossible to open one's eyes. As the aftershocks subsided, the two remained standing, their battle a stalemate!
Xiao Yan suppressed the surging blood and qi within him, but his eyes gleamed with excitement. He exclaimed, "Brother Lu, what a powerful sword technique! However, I've also gained some new insights!"

He gripped the Xuanzhong Ruler tightly, and strange flames ignited on its surface once more. He said in a deep voice, "My teacher previously taught me a mid-level Earth-rank ruler technique—the Ninefold Burning Mountain Ruler. I combined its profound principles with the Fusion Method of the Buddha's Wrath Lotus and incorporated them into that ruler just now. Otherwise, it would have been impossible to withstand your sword strike!"

Upon hearing this, Lu Yu's eyes revealed admiration, and he said, "You were actually able to fuse the Ruler Technique with the Fire Lotus? Brother Yan, your comprehension in combat techniques is truly extraordinary!"

"However, if your methods today stop here, you're still slightly inferior..."

Having said that, he suddenly stopped smiling, and his aura became ethereal and profound. The longsword in his hand, interwoven with blue and green, emitted a deep hum and slowly floated up, standing in front of him.

On the sword, the originally distinct blue and green colors began to permeate and merge with each other in an incredible way, eventually transforming into a chaotic and hazy gray sword energy, as if returning to the beginning of the world!
An indescribable aura of terror spread out, as if all things would be reduced to annihilation by this single sword strike. This power far surpassed the previous two strikes!
"Brother Yan, this is the final level of the Yin-Yang Returning to Origin Sword Technique—the Returning to Origin Realm!"

Lu Yu's voice was calm yet carried supreme authority, "Although this sword technique is a high-level Earth-rank skill, this final level is comparable to a Heaven-rank combat skill. Be careful!"

Xiao Yan sensed the destructive power contained within the hazy sword energy—power that made his soul tremble. His expression changed drastically, and he shouted almost without hesitation, "Stop! Stop! Brother Lu! I surrender! Quickly stop your divine power! This isn't a friendly spar, it's deadly!"

However, the moment he finished speaking, the chaotic gray sword energy suddenly dissipated like a tide, transforming back into blue and green flames that entered Lu Yu's body.

"Hahahaha!"

Seeing Xiao Yan's terrified expression, Lu Yu finally couldn't help but burst into laughter, saying with a carefree expression, "Just kidding! How could you master such a high-level Earth-rank fighting skill so easily? That sword strike just now was just a bluff to scare you!"

Xiao Yan was taken aback at first, then realized what was happening and was both amused and exasperated. He chuckled and scolded, "You little brat, Brother Lu! You even make jokes like that! You scared me half to death!"

He sighed, looking at Lu Yu's still playful face with a hint of curiosity in his eyes, and asked earnestly, "Brother Lu, just now... were you really unable to unleash that sword strike at all?"

Seeing this, Lu Yu stopped joking. His smile faded slightly, and a sharp glint flashed in his eyes. He said frankly, "With my current understanding of sword techniques, I am indeed still lacking in the complete 'Return to Origin Sword.' Forcing it would definitely backfire."

He abruptly changed the subject, and a wisp of that chaotic, hazy gray sword energy flashed past his fingertip once more. Though faint, it carried a chilling aura of destruction.

“However,” a confident smile returned to his lips, “it’s not impossible to only slash halfway through the sword, but doing so would be pointless.”

Upon sensing the fleeting yet terrifying sword energy, Xiao Yan's doubts vanished instantly, replaced by a wave of lingering fear. He quickly waved his hand and said, "Enough, enough! Don't even try with half a sword! I don't want to be truly cleaved in two by you!"

Lu Yu shook his head, dispelling the chilling sword energy from his fingertips, and laughed, "Don't worry, it's just a friendly spar, I won't really hurt you."

The two sat back down at the stone table, and the atmosphere returned to its previous harmony. Lu Yu seemed to remember something and asked, "Speaking of which, I haven't been back to the Black Corner Region for a long time. How is the Spirit Treasure Pavilion doing now?"

Upon hearing this, Xiao Yan revealed a hint of smugness, saying, "Sister Cai Lin is now a five-star Dou Zong. With her in charge, no one in the pavilion dares to cause trouble. However..."

He paused, a hint of surprise in his voice, and continued, "That girl Qinglin is even more remarkable. Her cultivation is a star higher than Sister Cailin's, and she's already a six-star Dou Zong."

"Oh?"

A genuine look of surprise flashed across Lu Yu's eyes as he exclaimed, "Qing Lin has made such progress? It seems that the benefits that the Jade Serpent Three-Flower Pupil and Xiao Cai have brought her far exceed expectations."

“It’s more than just cultivation level.” Xiao Yan continued with a smile, “According to your previous arrangements, I haven’t been idle. I’ve trained more than a dozen third- and fourth-grade alchemists for you, and also recruited two fifth-grade alchemists and one sixth-grade alchemist to join us. Now, the supply of pills from the Spirit Treasure Pavilion is second to none in the Black Corner Region.”

He took a sip of tea and added, "As for Qinglin, she's truly formidable. With her Azure Serpent Three-Flower Pupil, she has tamed five sixth-tier magical serpents and no less than thirty fifth-tier serpent magical beasts of various kinds for the Spirit Treasure Pavilion, forming a true 'magical beast guard snake team.' It is now the strongest guarding force of the Spirit Treasure Pavilion, and ordinary forces dare not provoke it."

After listening, Lu Yu couldn't help but smile with satisfaction: "I didn't expect that you would run Lingbao Pavilion so well during my absence. You must have worked hard."

"To what extent has your Burning Technique evolved?"

Upon hearing this, Xiao Yan scratched his head and said, "Mid-level Earth Rank, what's wrong, Brother Lu?"

"Mid-level Earth Rank... progress isn't slow."

Lu Yu nodded slightly, then his gaze became deep as he looked at him and asked, "So, what are your specific plans for the future? The evolution of the Burning Technique is ultimately inseparable from the Strange Fire."

Xiao Yan took a deep breath, a determined glint in his eyes, and lowered his voice to say, "To be honest, Brother Lu, I do have some ideas. I've heard that the Nine Dragons Thunderfire passed down through generations in Burning Flame Valley, and the incredibly mysterious Three Thousand Burning Flames sealed in the Pill Tower, are both ranked extremely high on the Strange Flame Ranking."

He looked intently at Lu Yu: "If I can obtain one of these two, my Burning Technique will surely evolve again, and my strength will experience a qualitative leap. However... neither of these places is easy to obtain, so we need to plan carefully and wait for the right opportunity."

Upon hearing this, Lu Yu nodded thoughtfully.

He wasn't interested in the Nine Dragons Thunderfire, as it wouldn't significantly improve his current strength. However, the Three Thousand Burning Flames were quite appealing to him.

Moreover, the spirit seed of the strange fire in his hand needs to grow rapidly, requiring a large amount of fire attribute resources. If he remembered correctly, the starry sky where the Pill Tower sealed the Three Thousand Burning Flames had accumulated a massive amount of fire attribute energy over the long years.

If one can find a way to guide the spirit of the strange fire to devour it, it will be enough to allow it to take a big step forward in its growth, and it may even break out of its shell ahead of time and take shape.

However, the Three Thousand Burning Flames were extremely ferocious, even the three giants of the Pill Tower were helpless against them. It would be difficult to succeed by relying on one's own strength alone, and some special external force would be needed...

Thinking of this, his gaze involuntarily turned to Zi Yan's room, a glint of shrewdness flashing in his eyes.

If he remembered correctly, the Three Thousand Burning Flames had a deep connection with the Ancient Void Dragon Clan. It was raised by a certain Ancient Void Dragon, and its origin contained an ancient dragon seal.

For this reason, it is extremely difficult to completely subdue it using ordinary methods.

To truly control this strange fire that has developed sentience, it is not possible to simply suppress it with power. The most crucial step is to delve into its soul space and obliterate its stubborn self-awareness in order to refine it.

This step requires the assistance of the Ancient Dragon Seal of the Void.

Thinking of this, Lu Yu turned to look at Xiao Yan and said in a deep voice, "Brother Yan, I am also quite interested in the Three Thousand Burning Flames..."

He didn't finish his sentence, but his meaning was already clear.

Upon hearing this, Xiao Yan was taken aback at first, then fell into a brief silence. He looked at Lu Yu's serious expression, and recalled the many ways Lu Yu had helped him and his teacher before, a resolute glint flashing in his eyes.

He quickly laughed heartily and patted Lu Yu's shoulder forcefully: "Haha, since you've taken a liking to it, Brother Lu, the Three Thousand Burning Flames are naturally yours! I only had two targets to begin with, so losing one won't make a difference. Besides, the Nine Dragons Thunderfire of Burning Flame Valley, in terms of its ferocity and power, might be more suitable for my ruler technique."

Xiao Yan's tone was relaxed and sincere, without the slightest reluctance: "In this way, we brothers can each get what we need. I'll go and plan the Nine Dragons Thunderfire, and you, Brother Lu, can focus on dealing with the Three Thousand Burning Flames. If you need any help, just let me know!"

Upon hearing this, Lu Yu felt a pang of guilt.

He naturally knew that with Yao Lao's connection, Xiao Yan was actually more likely to obtain the Three Thousand Burning Flames, while it would be difficult to obtain the Nine Dragons Thunderfire if he went to the Burning Flame Valley.

After all, that strange fire was a treasure passed down through generations of the Burning Flame Valley, and it was impossible for it to be traded.

He hesitated for a moment, then looked up at Xiao Yan and said sincerely, "Brother Yan, I owe you a debt of gratitude this time. Since you have given me the Three Thousand Burning Flames, if you ever get any news about other strange flames in the future, no matter when or where, you must tell me. I will definitely go and help you to obtain the strange flames as compensation for today."

With that, he flipped his hand, and a warm, smooth jade bottle appeared in his palm. Inside the bottle, five grains of spirit-nurturing powder, shimmering with white halos and radiating spiritual energy, were clearly visible. He handed the jade bottle to Xiao Yan.

"Your soul realm has now reached the peak of the mortal realm. These five grains of top-grade, four-colored, eight-rank spirit-nurturing dust will greatly benefit your soul nurturing and your breakthrough of the spiritual realm barrier."

"Once your soul enters the Spirit Realm, it will bring immeasurable benefits to your future control of strange fire, refinement of high-level pills, and even cultivation of battle qi. This item is most suitable for you."

Xiao Yan sensed the immense energy contained within the dust and knew it was incredibly precious. He quickly declined, saying, "Brother Lu, this is too valuable! The matter of the strange fire was entirely consensual; there's no need for such formality..."

Without a word, Lu Yu shoved the jade bottle into his hand and said with a smile, "We're brothers, why stand on ceremony? Take it, or I won't feel at ease."

"Besides, I won't be short of this in the future."

Unable to refuse, Xiao Yan looked into Lu Yu's determined gaze and felt a surge of warmth in his heart. He finally nodded emphatically and solemnly put away the jade bottle: "Since that's the case, then I'll accept it. Thank you, Brother Lu!"

(End of this chapter)