Liu Wuxie knew he couldn't waste this chance, so he pushed forward, aiming to reach the fourth-level Heaven Gaze Realm in a single charge.

He had already grasped three immortal arts in the astral domains, and now that he also possessed laws of the Fleeting Cloud Celestial Realm, he could attempt to cultivate a celestial realm's immortal art after he broke through. After all, only the immortal arts of the Fleeting Cloud Celestial Realm could slay an immortal from the celestial realm.

The mysterious axe grew increasingly clear, resembling an ancient divine axe that could split heaven and earth, carrying power beyond comprehension.

Even Liu Wuxie felt his heart clench as he watched it take shape. He knew the axe still had vast room to improve, and he would forge it into another trump card in the future. The power of the domain remained illusory in the end. Once he entered the celestial realm, he would have to reach the Immortal Lord Realm before he could unleash his own domain.

When the mysterious axe fell, countless cracks spread over the gate to the fourth-level Heaven Gaze Realm, yet it refused to split apart right away.

"Just as I expected. The fourth-level Heaven Gaze Realm belongs to the intermediate phase, and it won't be easy to make a breakthrough," Liu Wuxie said as he continued drawing his immortal energy.

Now that his immortal energy carried the laws of the celestial realm, he mobilized it at twice the previous speed.

The axe formed again, but this time it shrank until it looked like an ordinary axe. Then again, shrinking didn't mean weakening; it meant compressing everything and focusing all that power on a single point.

"Heaven and earth split!" Liu Wuxie roared. He didn’t know why those words left his lips, only that they felt etched into his soul, beyond explanation.

The axe descended with the momentum to split heaven and earth, shaking the air with loud rumbles as a primordial aura flooded his entire body. Every inch of his flesh and bone devoured it.

Liu Wuxie couldn't tell what the primordial aura truly meant. Humans could only trace their origins back to the Archaic and Primeval Eras, so did the Primordial Era come even earlier than those?

His physique, already in harmony with heaven and earth, began to strengthen, its strength surging as that unity deepened. In that moment, he became one with heaven and earth itself.

When the axe crashed down, the gateway to the fourth-level Heaven Gaze Realm shattered and fused into the desolate world, swiftly merging with the celestial realm's laws. As the celestial realm's laws increased inside the desolate world, they multiplied rapidly without end.

The instant Liu Wuxie broke through, a loud rumble rolled out from the depths of Nightmare City as his aura swept outward like a storm.

Perhaps sensing danger, the Seven-Fiend Netherworld Chains trembled violently, and the entire city shook along with them. One hundred million astral crystals detonated, turning into a torrent of liquid energy that poured into the desolate world.

With that, he had burned through four to five hundred million astral crystals out of the one billion he had obtained from Peach Blossom Cave. If he kept spending them at this pace, he would run out before reaching the pinnacle of the Heaven Gaze Realm. Obtaining more astral crystals wouldn't be easy either, because he couldn't possibly rob the entire astral domain.

A dull ache throbbed behind Liu Wuxie’s eyes. He couldn't reach the celestial realm without stepping into the Immortal Realm, yet every future breakthrough would demand more astral crystals, and one billion would only cover the bare minimum.

An immortal stone appeared in Liu Wuxie's hand, and the celestial realm's laws crushed it directly, converting it into boundless immortal energy that surged into the desolate world. The number of laws began to rise again, and they could now condense into an immortal art from the celestial realm.

Liu Wuxie pushed through the final stretch of his breakthrough. He could sense Nightmare City’s artifact spirit straining to break free, while the Seven-Fiend Netherworld Chains began to loosen. The spirit seized this opening to corrode its restraints.

As the Desolate Devouring Art circulated, he devoured every trace of evil energy within a radius of thirty thousand miles. After all, not everything in the world required spiritual energy for cultivation, and with Liu Wuxie's abnormal physique, he could cultivate with any energy in existence.

The Sky Devouring Divine Cauldron refined the evil energy at a terrifying speed, converting it into yellow liquid that flowed into the desolate world. If he had an alternative, he had no intention of continuing to burn through astral crystals.

Many evil spirits hadn't gone far and were hiding nearby. The moment the hindrance of evil energy vanished, they fled the Nightmare City. The desolate world began to expand as cracks split the ground, and boundless energy gushed through those fissures.

Ariel didn't understand what was happening, as she didn't know how to cultivate her current form after losing all her memories. Even so, the sudden surge of energy poured into her, forcibly raising her cultivation.

Once Liu Wuxie found the Angel Spring and helped her restore her true form, she would definitely be able to reach the Immortal Realm. The Angel Spring had long vanished from the surface of the world. It was said to exist only among the angel race, yet the angel race itself had already vanished from the world.

Time crept by, and the artifact spirit broke half of the restraints. If it had another half a day, it could escape from this place, and even if it abandoned Nightmare City, it could cultivate again from the very beginning.

The Desolate Devouring Art began to circulate even faster. Many cultivators had died after entering Nightmare City, and their corpses lay hidden in its depths. Even the treasures in their interspatial rings couldn't escape Liu Wuxie as he refined them. After advancing, the Desolate Devouring Art had grown even more powerful.

By noon, Liu Wuxie's aura finally settled at the late phase of the fourth-level Heaven Gaze Realm, only one step away from the pinnacle. The five divine gates in Liu Wuxie's soul sea also released boundless divine force. The stronger his divine force became, the more terrifying his mythical arts would grow.

"You want to leave?"

Liu Wuxie's eyes snapped open, and he caught the artifact spirit trying to escape. He immediately formed seals that shot into the underground world, then reinforced them.

The artifact spirit roared in frustration the moment it saw the seal strengthen when it was about to slip away.

"Damn it! Damn it all!" the artifact spirit screamed after the seal immobilized it. Now, it could only hide inside the light sphere and wait for Liu Wuxie to refine it.

Liu Wuxie had promised in the past that he would help it advance to an immortal artifact, but since the artifact spirit had tried to play tricks, he wouldn't mind enslaving it for eternity.

After sealing the artifact spirit, Liu Wuxie continued perfecting the desolate world. Not until late at night did his cultivation truly consolidate, and every tree in the desolate world now carried runes, their quality drastically improved by the baptism of the celestial realm's laws.

A random piece of tree from the desolate world could now be forged into an artifact, yet Liu Wuxie naturally wouldn't go chopping down trees while the world was still growing.

"Time to cultivate an immortal art from the celestial realm," Liu Wuxie said after opening his eyes and gazing at the sky.

Even quasi-immortals couldn't peek through the celestial realm's gate, but Liu Wuxie had managed it. Even so, the gate still couldn't be opened, as he had to reach the Celestial Realm if he wanted to ascend.

He still couldn't control a truly powerful immortal art because he needed something that matched his current immortal energy.

The cultivation technique he cultivated in his past life, the Primal Heavenly Dao Art, was undoubtedly a top-tier cultivation technique in the celestial realm. Many immortal arts he had grasped relied on the Primal Heavenly Dao Art as their foundation because they complemented each other.

If one cultivated a demonic technique, one naturally couldn't unleash the celestial realm's immortal art, and if one cultivated an immortal technique, one likewise couldn't unleash demonic art.

That meant even if Liu Wuxie ascended to the celestial realm one day, he would have to abandon most of the immortal arts he had mastered in his past life unless he switched from the Desolate Devouring Art to the Primal Heavenly Dao Art.

He had never considered starting all over again, because the Desolate Devouring Art was definitely superior to the Primal Heavenly Dao Art. That was also why he hadn't dared to attempt cultivating a celestial realm's immortal art before.

Since he cultivated a different technique in this lifetime, trying could trigger internal conflict, and even if he somehow succeeded in cultivating a celestial realm's immortal art, its power would drop drastically.

The various sects had researched cultivation techniques that perfectly matched their martial techniques, and the Desolate Devouring Art demanded far more of the immortal arts. That meant ordinary immortal arts wouldn't satisfy him.

Then again, Liu Wuxie knew countless immortal arts, and one would surely suit the Desolate Devouring Art. Not to mention, the Desolate Devouring Art could encompass everything in the world aside from a select few immortal arts.

He searched through his memories, yet finding a powerful immortal art without a harsh requirement of immortal energy proved difficult, and he also needed one that wouldn't consume too much.

Countless immortal arts flashed through his mind before he picked one.

Liu Wuxie made his decision. "Nine Absolute Fist, let's go with you!"

This fist technique carried boundless might, but mastering it wasn't simple. It required gathering nine elements as the base requirement, but it didn't impose a harsh requirement on immortal energy.

Other cultivators found it nearly impossible to gather nine different elements. Even in Liu Wuxie's past life, he had only gathered eight, and even he had never grasped this immortal art. However, in this lifetime, things were different due to the countless energies within the desolate world. Ninety elements would pose no problem for him, let alone nine.

This immortal art allowed power to overlap nine times, each layer stronger than the last, and that alone showed its terror, as though it combined nine immortal arts into one.

"This is a decent fist technique, and it perfectly suits me."

Liu Wuxie smiled after selecting an immortal art. Once he grasped it, he would even dare to clash with ordinary immortals head-on, though he still couldn't say for certain whether he could kill them given his low cultivation. But if he reached the Quasi-Immortal Realm, he would be able to butcher immortals with ease.

He even borrowed the Heavenly Dao Book's help to master the Nine Absolute Fist quickly. He only needed an hour to perfect the cultivation method as the Heavenly Dao Book removed imperfections and further strengthened it.

Then again, it remained only an ordinary immortal art, and even after perfection, it still couldn't compete with a top-tier immortal art. However, for now, it was more than enough.

The celestial realm couldn't send anyone too powerful, as just their aura alone could destroy the mortal realm. At that point, it wouldn't only become the mortal realm's disaster; the celestial realm would face disaster as well.