"Master, these negative energies are the best cultivation resource for us, but given our current strength, they are simply too potent. We don't dare absorb them."
The Heart-Devouring Demon slaves within the Phantom Tower seemed restless, transmitting their thoughts to Ye Yunfei.
"It's fine. If you wish to absorb them, do so quietly. I will cover for you," Ye Yunfei said.
"Wonderful! Thank you, Master!"
Hearing Ye Yunfei's words, the Heart-Devouring Demons grew excited. They quietly emerged from the Phantom Tower, concealing themselves around Ye Yunfei's body.
With a thought, Ye Yunfei released his Mental Force energy, beginning to resist the violently churning negative energies surrounding him.
At that moment, hidden in a space nearby, a Heart-Devouring Demon was observing Ye Yunfei.
"This human's resistance to negative emotions seems somewhat strong," the demon mused, secretly astonished to see Ye Yunfei standing there so long, apparently unaffected.
"He's just a mere Initial Golden Immortal. I refuse to believe his soul body has such formidable willpower. I will surely be able to crush his spirit using emotional energy."
The Heart-Devouring Demon was confident, having used negative emotions to defeat many Initial Golden Immortals in the past.
Boom...!
The demon released even greater torrents of negative emotional energy, surging towards Ye Yunfei like a raging tidal wave. Boundless negative power utterly transformed this stretch of space into a gloomy, desolate, oppressive, and somber realm. Heart-wrenching sobs endlessly assaulted Ye Yunfei's ears.
"That fellow is intensifying his attack on me," Ye Yunfei thought inwardly.
With another mental command, Ye Yunfei released more Mental Force energy, condensing it into an invisible protective barrier that tightly shielded the small area he occupied, resisting the assault of the negative emotional energy.
The Heart-Devouring Demon slaves, hidden beside Ye Yunfei, continuously refined and absorbed the negative emotional energy around them. Under Ye Yunfei's protection, they could absorb the potent negative energies without any interference.
"So this brat has cultivated Mental Force, and his level is fairly high. No wonder he's lasted so long," the Heart-Devouring Demon in the distance gritted its teeth upon sensing Ye Yunfei's Mental Force energy.
"Heartbreak Art!"
The demon unleashed a secret technique.
Immediately, Ye Yunfei found masses of sorrowful, weeping beings appearing in the space around him. They all seemed to have suffered the greatest misfortune in the world. Their mournful cries, filled with grievance and lament, were unbearably tragic and haunting.
These sobs were like a sonic Martial Skill, continuously pouring into the depths of Ye Yunfei's soul sea.
The sound of so many beings weeping together created a suffocating atmosphere of sorrow. In such an environment, Ye Yunfei was affected and found himself feeling inexplicably heartbroken.
"Be careful. This Heart-Devouring Demon is quite powerful. Don't let his negative emotional energy influence you."
At that moment, the Remnant Soul's voice suddenly transmitted to Ye Yunfei. It sounded like a morning bell or dusk drum, instantly bringing clarity and sobriety. Clearly, he was using some secret technique to help Ye Yunfei resist the demon's attacks.
"This Heart-Devouring Demon is indeed formidable, but rest assured, elder. I can still resist it," Ye Yunfei transmitted back, knowing the Remnant Soul was assisting him.
"I hadn't realized your attainments in Mental Force were this profound," the Remnant Soul praised.
Ye Yunfei had seldom used Mental Force to face enemies in front of him before, so he only now realized Ye Yunfei's high level.
"Art of Terror."
Seeing Ye Yunfei still standing there, seemingly unaffected, with heavenly thunder continuing to fall from above, the distant Heart-Devouring Demon grew angry and unleashed another emotion-based energy technique.
Suddenly, all kinds of terrifying scenes manifested around Ye Yunfei. Countless ferocious ghosts, vengeful spirits, fierce birds and beasts radiating bloodlust, and other horrors filled the space.
Ye Yunfei was instantly enveloped by an atmosphere of terror. Everything he heard, saw, and perceived with his Soul Power energy was filled with dreadful images.
"This is the energy of terror. The Heart Devourer Race can use negative emotional energy to cast all sorts of bizarre skills and secret techniques. You must fortify your will and stabilize your soul body, lest you be influenced by that negative energy," the Remnant Soul said, seeming quite familiar with the Heart Devourer Race.
"Thank you for the warning, elder."
Ye Yunfei released his Mental Force energy without reservation, creating a tight defensive perimeter around his body. Simultaneously, his two soul bodies sat cross-legged within his soul sea, as still as monks in deep meditation, strenuously repelling the influence of the surrounding horrors.
"What's going on? I still can't subdue this brat. He's just a mere Initial Golden Immortal. How can he possess such an unshakeable will? The techniques and secret arts I'm using don't seem to have much effect on him."
Seeing that Ye Yunfei still remained unaffected, continuing to undergo his tribulation, the demon realized the process was nearing its end. It wouldn't be long now.
"My tribulation is almost over. It's time to deal with this fellow," Ye Yunfei thought as his gaze swept toward the demon's location.
By now, Ye Yunfei had discerned the demon's strength—roughly equivalent to a High or Peak Golden Immortal. Its attack methods were just extremely bizarre and difficult to handle.
"Master, I've refined and absorbed a massive amount of negative emotional energy. The gains are substantial," the Heart-Devouring Demon slaves transmitted excitedly, having continuously absorbed the energy.
"Conceal your auras, all of you. I intend to lure him over and deal with him. Wait until I subdue him; then you can come out and absorb his energy," Ye Yunfei ordered, worried their presence might alert the demon.
"Very well, Master. We'll hide immediately."
The demons quietly retreated into the Phantom Tower. Then, Ye Yunfei suddenly displayed an expression of intense agony and terror, standing there trembling.
"Haha...! This human brat can't hold on any longer! Now you know my power!"
The distant demon roared with laughter upon seeing this.
"Now, immediately disrupt this brat's tribulation! Force him to generate a torrent of negative emotions for my enjoyment!"
Overcome with excitement, the demon revealed itself, instantly appearing right before Ye Yunfei.
Ye Yunfei had been waiting for it to get close.
With a thought, a treasure pearl shot out from within his body.
The Heart-Refinement Pearl! This was a Mental Force-class magic treasure given to Ye Yunfei by Mr. Liu long ago.
Ye Yunfei made the pearl hover above his head for protection, then suddenly exploded into action. Drawing a longsword, he executed the Ten Thousand Swords Returning to One technique, sending wave after wave of thick sword beams continuously slashing against the Heart-Devouring Demon's physical body.
At the same time, his other hand clenched into a fist, and he punched the demon's body again and again.
The Heart Devourer Race excelled at Mental Force. Although their physical bodies were also robust and possessed considerable combat strength, they were no match for Ye Yunfei in close-quarters melee combat—Ye Yunfei's current fighting power already rivaled that of a Primary Heavenly Immortal.
Under the dual assault of Ye Yunfei's swordsmanship and physical power, the demon's body was soon shattered, leaving only its Soul Body.
"Damn you, brat! You weren't affected by my negative energy at all! You deliberately lured me here!"
The demon roared in shock and fury.
"Correct," Ye Yunfei said with a smile.
"Just you wait, brat! I hail from Demon Capital! How dare you shatter my body! I will return for vengeance!"
With its body destroyed, the demon lost its will to fight, intending to flee and recover.
"And you think you can leave?"
Ye Yunfei sneered. As his voice faded, a monstrous expanse of ghostly mist suddenly erupted, instantly engulfing the area. Dense masses of vicious ghosts and vengeful spirits surged forth from the mist, promptly sealing off the demon's escape routes.
"You practice Ghost Cultivation!"
The Heart-Devouring Demon stared in terror at Huang Shang, who strode from the churning ghost mist.
He knew well that ghost cultivators were the natural banes of all soul bodies. In his current Soul Body state, facing a powerful Ghost Cultivator filled him with dread.
The next moment, Ye Yunfei and Huang Shang attacked simultaneously. Ye Yunfei assaulted the demon with his Mental Force energy and both his soul bodies, while Huang Shang deployed ghostly arts specifically designed to counter soul bodies.
Under their combined assault, the Heart-Devouring Demon could not withstand them for long. Finally, its Soul Body was jointly subdued and controlled by Ye Yunfei and Huang Shang.
"Master, perfect! We need his negative emotional energy for our cultivation!"
At this moment, the group of Heart-Devouring Demon slaves hurried out from the Phantom Tower, their eyes gleaming with avarice as they gazed at the subdued demon. Its vast reserves of negative emotional energy were premium cultivation resources for them.
"You are of our race! Why do you aid this human, even calling him Master? What is the meaning of this?"
The subdued demon stared at the demon slaves in shock and fury.
"I understand! You all must have entered a Heart-Oath with this human and are now his slaves," it said, quickly figuring out the situation.
"Indeed. We are all our Master's slaves now. You dared to provoke our Master. Regret it now, don't you?"
The demon slaves sneered coldly at their subdued counterpart.
The Heart Devourer Race was cold and emotionless, harboring little sentiment for their own kind. Bound by the Heart-Oath, their loyalty lay solely with Ye Yunfei.
"Despicable human! You dare to force members of our race into a Heart-Oath with you! This is an insult to our entire race! A capital crime! Do you not fear invoking the wrath of our race?"
The subdued demon roared.
"It is your people who have always come looking for trouble with me. Take just now, for instance. You came for me. So, your words are pointless."
Ye Yunfei spoke coldly.
"Now you may die."
He looked at the Heart-Devouring Demon with an indifferent gaze, his tone casual.
"You all proceed. Drain his negative emotional energy. Elder Huang, his Soul Body is yours."
Ye Yunfei ordered.
"Thank you, Master!"
The demon slaves immediately rushed forward and began refining and absorbing the captive demon's negative emotional energy.
"Get away from me, you traitors! Or I will make sure you regret it!"
The captive demon cried out in panic and fury.
At this point, all the negative emotional energy he had cultivated over his lifetime was stored within his Soul Body. If drained completely, his cultivation would vanish entirely.
"You're facing death's door. Do your threats hold any water now?"
The demon slaves paid his threats no mind. Like hungry wolves descending on their prey, they began frantically dividing his negative energy.
"Heh heh... Your Soul Body belongs to me now. I shall savor it slowly."
Huang Shang's pitch-black, lustrous ghost form stood before the demon, uttering a cold laugh.
"How dare you!"
The demon was terrified, feeling Huang Shang's aura in his vulnerable Soul Body state.
By now, Ye Yunfei's Lightning Tribulation had ended.
"Intermediate Golden Immortal."
Ye Yunfei felt the torrents of immortal power energy surging within his body and spoke softly.
Though only an Intermediate Golden Immortal, Ye Yunfei was confident that his current immortal power could overwhelm the vast majority of Golden Immortals. Even Peak Golden Immortals on the level of Nine-Nine Return to Origin Perfected Immortals might not compare.
"Wait! Human! I don't wish to perish like this! I am willing to form a Heart-Oath and become your slave! Spare my life!"
Suddenly, the Heart-Devouring Demon cried out.
Unable to withstand the pressure of imminent death, he had chosen to submit to Ye Yunfei.
"Oh? You are willing to form a Heart-Oath with me?"
Ye Yunfei looked over and asked.
"Yes. As long as you do not kill me, I am willing," the demon said dejectedly, knowing he had no other choice.
"Fine. If you are willing to form a Heart-Oath, I will spare your life."
Ye Yunfei thought for a moment, then nodded in agreement. He certainly wouldn't refuse an additional slave with Golden Immortal strength.
"Everyone, stop."
Ye Yunfei commanded.
The demon slaves and Huang Shang immediately ceased and withdrew.
"Good. Now, begin," Ye Yunfei said.
"As you wish," the Heart-Devouring Demon replied, hanging its head in defeat.
Subsequently, Ye Yunfei brought the demon into the Phantom Tower to commence the Heart-Oath.
Roughly one hour later.
Ye Yunfei and the Heart-Devouring Demon successfully completed the Heart-Oath.
"Master."
The demon's weakened Soul Body stood respectfully beside Ye Yunfei.
Thus, Ye Yunfei gained another slave with Golden Immortal strength.
"Rest and recuperate properly. Strive for a swift recovery."
Sensing the demon's weakened state, Ye Yunfei offered a few words before sending it into the Phantom Tower for secluded healing.
"Two days remain until the Void Secret Realm opens."
Ye Yunfei calculated the days.
Meanwhile.
Within another world of the Tiange World Cluster.
"Well? Have you found that kid yet! He sided with those Xiao bitches, killed so many of our Black Wind Group brothers! This grudge must be settled! How can our Black Wind Group operate if we don't avenge this!"
A petty boss of the Black Wind Group shouted.
"Spread my orders! We must find that kid and kill him!"
The boss emphasized his command.