"Senior Brother, Senior Brother, I was wrong." Qi Feifei was utterly terrified, her figure transforming into a faint, flickering mist of peach-red, darting left and right, yet utterly unable to escape the assault of the three malevolent Ghost Guards. With Qi Feifei only at the third layer of the Foundation Establishment stage, dealing with these three Ghost Guards was already a monumental struggle, let alone having the unfathomably powerful Lei Dong watching intently from the side.

This kind of formation left her feeling utterly powerless, so much so that she dared not even retaliate. All she could do was adopt a pitiable posture, begging for mercy. She knew well that Lei Dong had seen through her malicious intentions; any further insistence on false denials would only hasten her demise. Crying out in a delicate, mournful voice, she pleaded, "Senior Brother Lei, it truly was my fault. I shouldn't have been possessed by greed and secretly followed you. I am willing to atone for my error; whatever you wish, Senior Brother, I will comply."

"Hmph, a flighty woman like you, how could you possibly be worthy of this Lei? I advise you to accept your death obediently, lest you suffer the agony of being devoured by ten thousand ghosts and having your soul refined by Nether Fire." Lei Dong snorted contemptuously. Not long after engaging the Purgatory Fire Ox, he had already detected Qi Feifei sneaking in with her secret techniques, thanks to his exceptionally keen spiritual sense. However, Qi Feifei also dared not make a move rashly, as Lei Dong’s three unused Ghost Guards were openly positioned in ambush. What deterred Qi Feifei even more was the extremely formidable Purgatory Fire Ox; even if she had managed a sneak attack to kill Lei Dong, she likely wouldn't have escaped the Fire Ox afterward.

Therefore, Qi Feifei chose to wait—waiting for the moment the mussel and the snipe fought so the fisherman could profit. In her mind, although Lei Dong was powerful, his cultivation was still a half-step below hers, and she had immense faith in her own evasion techniques. She believed that by lying in wait while Lei Dong was locked in intense battle, he shouldn't detect her.

"Senior Brother Lei," Qi Feifei said, weaving and dodging, narrowly avoiding the Ghost Guards several times. Her face paled further in fright. "My cultivation is the Su Nü Cauldron Furnace Great Art. I am still a virgin. If Senior Brother is willing, I offer my immature Yin Core Essence to you."

The Su Nü Cauldron Furnace Great Art? Lei Dong’s heart stirred. He had certainly heard of this famous technique from the Yin Yang Harmonious Union Sect, one of the Eight Great Sects. It was a marvelous art requiring cultivation to begin at a very young age, placing extremely high demands on every aspect of the practitioner’s constitution.

The actual combat prowess of this art was unremarkable and certainly not fit for the main stage. However, it possessed an exceptionally peculiar feature: during its practice, the cultivator used their own body as a cauldron to gradually refine a Yin Core. As the cultivation deepened and time passed, the Yin Core would slowly mature. Only when reaching the peak of the late Foundation Establishment stage, standing on the precipice of the Core Formation bottleneck, would this art reveal its greatest advantage.

At that juncture, engaging in dual cultivation with a male partner would instantly bring immense benefits to both parties. The female cultivator practicing this art could integrate the Yang Essence absorbed during the Yin-Yang union into her own Yin Core, achieving perfect harmony. There would be a very high probability of transforming the Yin Core into a Golden Core in one fell swoop, thereby becoming an influential figure on the Golden Core path. The male, conversely, would acquire the primordial Yin essence she had accumulated throughout her life during this intimate exchange. If he happened to be at the Great Perfection of the Foundation Establishment stage, his chances of smoothly breaking through and advancing to the Golden Core stage would increase dramatically.

Thus, it was a cauldron art that benefited both parties, aligning perfectly with the principles of the Yin Yang Harmonious Union Sect. With a bit of luck, it could suddenly add two Golden Core cultivators to the sect.

Of course, practicing this art was not without prerequisites. First, one must possess sufficient innate talent; otherwise, even if all other conditions were met, poor aptitude would prevent reaching the Great Perfection of the Foundation Establishment stage. Second, one needed to possess the Su Nü physique. Lei Dong knew nothing about how to identify or define the Su Nü physique. But he did know that among a hundred women with spiritual roots, one might not even possess the Su Nü physique. Consequently, although this art of the Yin Yang Harmonious Union Sect was renowned, few could actually cultivate it. Naturally, the Yin Yang Harmonious Union Sect had considered trading disciples with Su Nü physiques with other sects, but none of the other eight top-tier sects were willing to engage in such dealings.

After all, if they successfully helped one disciple of the Yin Yang Harmonious Union Sect reach fruition, there was a high chance of producing two Golden Core masters. Over time, wouldn't the entire world eventually be dominated by the Yin Yang Harmonious Union Sect? But despite their opposition and apprehension, every cultivator, even those already at the Golden Core stage, desperately coveted women practicing the Su Nü Art. After all, taking the long-accumulated Yin Essence from her was equivalent to an extremely rare, top-grade medicinal pill. It might not even be an exaggeration if it could facilitate a breakthrough from the first layer of the Golden Core stage to the second. However, the best effect was achieved by 'consuming' this pill when one was at the Great Perfection of the Foundation Establishment stage; the resultant increase in the chance of Core Formation far surpassed any known Core Formation elixir in the world.

Lei Dong, of course, could not help but be tempted. He was acutely aware of the limitations of his own spiritual root aptitude. Breaking through the bottleneck at the peak of the second layer of the Foundation Establishment stage was proving incredibly difficult. He could only imagine how arduous it would be to step onto the path to the Golden Core stage from the peak of the twelfth layer of the Foundation Establishment. Forget about himself; even those with peerless talent, after enduring countless hardships and diligently cultivating to the Great Perfection of the Foundation Establishment, often found themselves permanently stuck at this final threshold, eventually dying as their lifespans waned, filled with regret. Historically, those who met this fate were as numerous as carp crossing a river.

Seeing Lei Dong frowning, his face etched with indecision, Qi Feifei cursed inwardly that all men in the world were birds of a feather, yet she cried out with even greater desolation and pathos, "Senior Brother, not only am I willing to surrender my Yin Core Essence, but I am also willing to serve Senior Brother for a lifetime."

Unexpectedly, Lei Dong, who had been deeply considering the offer, felt a jolt in his heart upon hearing her declaration of lifelong servitude. The vision of Ding Wanyan’s peerlessly beautiful and gentle face flashed in his mind, and the oaths they had sworn echoed in his ears. His expression suddenly turned cold. He urged the three Ghost Guards to intensify their attack, his features stern: "Qi Feifei, don't try to play games with this Lei. If I let you go today, you will incite others to kill me tomorrow. Therefore, your so-called Yin Core Essence, while pleasant to hear about, is ultimately an illusion to me and will only bring disaster. So..."

"It is better for you to die cleanly."

Lei Dong let out a low roar, flicking his hand. The long-prepared Annihilation Dharma Wheel, accompanied by a mournful, whimpering cry, shot straight towards her.

Qi Feifei was, after all, a top disciple from a supreme sect. Although the Su Nü Art had weak offensive capabilities and limited combat strength, its defensive and evasive abilities were quite good. The peach-red mist churned as she flashed away, narrowly taking a blow from an enraged Ghost Guard. Simultaneously, a sash as smooth as silk, crimson in color, unfurled, swirling around her body. Suddenly, it shot out like a serpent, coiling towards Lei Dong’s Annihilation Dharma Wheel.

Screech.

The azure light and the red light collided, producing a grating sound like tearing fabric. The Annihilation Dharma Wheel spun rapidly, tearing at the sash until it seemed utterly shredded, only then losing momentum. That icy aura, however, had already terrified Qi Feifei, leaving her pale and flustered. This was the first time in her life Qi Feifei felt so close to death. The powerful Senior Brothers of the past would all become hopelessly infatuated with just a little coquetry and a few sweet words. Yet, this Lei Dong was not only overwhelmingly powerful in skill, but his resolve was also as hard as iron. No matter how pitifully she begged, he remained unmoved.

Although Lei Dong coveted the Su Nü Core Essence, that treasure would only become truly useful when Qi Feifei reached the late Foundation Establishment, the peak of Great Perfection. Even drawing her Yin Core Essence now would only yield mediocre results. The late Foundation Establishment was too distant a prospect for Lei Dong to bank on. At that, his whole body erupted with spectral Nether Ghost Qi, his figure flickering and shifting like a phantom, blocking Qi Feifei’s retreat. He raised the Myriad Ghost Banner and recited an incantation.

Hundreds of savage and ferocious vengeful spirits, howling mournfully, swept towards Qi Feifei like a tide of insects, dense and suffocating.

Qi Feifei's heart sank into utter despair. Although her movement techniques and the protection of the crimson sash could temporarily hold off the swarm of fierce ghosts and allow her to weave and dodge the attacks of the three Ghost Guards, this was only a temporary reprieve. Her greatest asset, her arts of seduction, seemed completely ineffective against this man whose heart was cold as ice.

Even ants cling to life. How could a woman as vibrant and self-assured as Qi Feifei possess the will to meet death heroically? A savage look flashed across her face; she gritted her teeth and cried out mournfully, "Senior Brother Lei, I am willing to open my heart and allow you to refine my soul and leave your mark."

Lei Dong’s movements immediately slowed. He looked somewhat disbelieving. "You mean, you are willing to let me perform the Soul Refining Fusion technique? To become a Ghost Slave under my control?" This Soul Refining Fusion technique was a common art in the Cultivation World. Once the soul was refined and a brand left upon it, one’s destiny was sealed as a servant for life. Consequently, any person with a shred of willpower would absolutely refuse such an outcome. To surrender one's very right to life to another, to regard them as master without the slightest thought of disobedience—in Lei Dong's view, existence under such terms was worse than a swift death.

"Yes." Qi Feifei dodged desperately, her beautiful face etched with utter despair, a mixture of unwillingness and helplessness. "However, I am not without conditions. I only ask that Senior Brother make an oath. Once we engage in dual cultivation, and you have taken my Yin Essence and gained your benefit, you must release the soul refinement control and allow me my freedom. Otherwise, I would rather suffer the torment of ten thousand ghosts devouring my soul and simply die clean."

Hearing these words, Lei Dong found her stance suddenly more reasonable. If she were truly willing to surrender her soul to his control for her entire life, even beyond death, Lei Dong would find it unbelievable.