The black stone was no larger than a basin, yet its warped outline looked nothing like an ordinary rock. After all, a normal stone would reveal clear veins the moment it cracked open.

This black stone showed no veins at all; only etched patterns crawled across its surface. Those marks interwove like natural roots, and seeing roots "grow" over stone felt unnervingly wrong.

Liu Wuxie's thoughts raced as he tried to pin down the black stone's origin. He knew he had sensed the aura leaking from it before, yet too much time had passed and too many memories had slipped away.

This was his second life, and the memories of his first had faded until only fragments remained. Only hatred stayed carved into his heart, and he knew he would never forget that.

He rummaged through those buried recollections for a long time before his eyes suddenly narrowed. At last, he remembered what this stone truly was. Not many people in the astral domains could recognize it, including Hua Feiyu, as this black stone should not have existed in the astral domains at all.

"How could the Indigo Bamboo Astral Domain possibly produce Indigo Thunderwood? This is unbelievable! It only exists in the celestial realm, and no one can find it in the mortal world," Liu Wuxie murmured. The thing in his hand looked like a black stone, but it wasn't a stone at all, but a segment of an Indigo Thunderwood.

The Indigo Thunderwood was a mythical tree that drew lightning once it grew to a certain size. It didn't start black; it started indigo, only to turn charred black after heavenly lightning struck it repeatedly.

But how had a segment of the Indigo Thunderwood ended up in the astral domains? Liu Wuxie felt completely at a loss and could only wonder if the mysterious gate had spat it out.

If that were true, then the mysterious gate would appear every tens of thousands of years, and this piece of Indigo Thunderwood had likely surfaced in the Indigo Bamboo Astral Domain long ago. No one had recognized it, and even a quasi-immortal couldn't split it open.

Yet its unusual patterns had an aesthetic appeal, so the Evil Spirit King hadn't discarded it. At first glance, those markings looked chaotic, but each line stayed crisp, and that sharpness felt strange. Without those runes, the Indigo Thunderwood would've been tossed away as junk a long time ago.

"What a treasure!" Liu Wuxie grinned as he gently stroked the Indigo Thunderwood.

Although others couldn't refine it, he could. The Sky Devouring Divine Cauldron could swallow and refine anything in the world.

Heavenly lightning had tempered the Indigo Thunderwood for countless years, and potent heavenly lightning filled it. Yet the truly frightening part wasn't the lightning but the celestial realm's laws sealed inside.

No matter how many immortal runes Liu Wuxie absorbed in the Indigo Bamboo Astral Domain, or how many quasi-immortals he refined, none of them compared to absorbing a single immortal rune from the Fleeting Cloud Celestial Realm. That was the vast difference, and there was no comparison between the two.

This segment of the Indigo Thunderwood had grown for thousands of years, drawing in countless immortal runes and laws of the celestial realm.

"This is great! With this Indigo Thunderwood, I'll be able to make my breakthrough to the fourth-level Heaven Gaze Realm. Once I make my breakthrough, I'll have a higher chance of severing the Seven-Fiend Netherworld Chains!"

Liu Wuxie immediately tossed the remaining items into the Sky Devouring Divine Cauldron.

The mountain of loot vanished completely, leaving only the Indigo Thunderwood in his grasp. After more than a full day, the desolate world absorbed all the energy from the loot. Several realms formed one after another, and some emerged that even Liu Wuxie couldn't identify.

That didn't surprise him; countless minor races could rise and fall within a few centuries, then vanish before the world ever remembered their names.

Liu Wuxie planned to refine the Indigo Thunderwood and force another breakthrough. After reaching the fourth-level Heaven Gaze Realm, he would even dare to contend with an ordinary immortal.

He no longer feared cultivators at the first-level Heavenly Immortal Realm, but he worried the celestial realm might send someone beyond the Heavenly Immortal Realm after him. No one understood the cultivation realms in the celestial realm better than he did.

Most ordinary people remained in the Heavenly Immortal Realm. Above that came the High Immortal, True Immortal, Spirit Immortal... and then the Immortal King Realm.

Once someone reached the Immortal King Realm, they qualified to establish a sect. Even so, the Immortal King Realm still couldn't count as a powerhouse in the celestial realm, and even a sect they founded would be small at best.

Only cultivators who reached the Immortal Lord Realm held real standing in the celestial realm. Above that stood the Immortal Venerable Realm, the Immortal Regnant Realm, and the Immortal Emperor Realm.

In his previous life, Liu Wuxie had been an orphan, taken in by others and guided by his master, the Heavenly Taoist. He had spent only a few centuries becoming an Immortal Emperor.

That meant a long road still stretched ahead, yet Liu Wuxie didn't feel discouraged. He believed the Desolate Devouring Art, the Sky Devouring Divine Cauldron, and the Heavenly Dao Book would carry him back to the celestial realm sooner than anyone imagined.

He had to repay the blood debt from his previous life, or his dao heart would never become whole. After he adjusted his spirit and energy and brought his soul to its peak, he finally chose to refine the Indigo Thunderwood.

The Sky Devouring Divine Cauldron had long since merged with the desolate world, so he only summoned a black hole to devour the Indigo Thunderwood. The instant the black hole swallowed it, black demonic flames wrapped the wood and began breaking it down.

As days passed, a vast number of cultivators arrived in the Outer Astral Spacetime. The mysterious gate had stopped spewing items in the last few days, as though it was preparing for a fiercer eruption, and the gathered cultivators clashed daily.

The Heavenly Dragon Sect and the Heavenly Dao Society had also dispatched experts. One sect after another built camps around the gate, claiming favorable terrain.

Three days later, a crack finally split through the Indigo Thunderwood, and boundless force surged out. Liu Wuxie's eyes snapped open, and a smile curled his lips.

"That's right! It's this familiar aura!" Liu Wuxie said. He finally felt the Fleeting Cloud Celestial Realm's power once more, and even as a mere wisp, it brought a drastic transformation the moment it entered the desolate world.

The desolate world didn't expand outward, nor did it grow denser. Instead, the laws began to shift with every strand of immortal energy and immortal rune infused by the Fleeting Cloud Celestial Realm's aura.

Words couldn't describe this transformation; only the cultivator himself could feel it. Like water, it might appear ordinary on the surface, yet some carried unseen essences capable of nourishing and reshaping a person from within.

Liu Wuxie's cultivation didn't change, yet his strength surged rapidly as his immortal energy transformed. It stayed gold, but more strange runes surfaced within it.

Liu Wuxie recognized those as laws unique to the celestial realm that the desolate world had assimilated, and the number of immortal runes began to climb as well. Once he refined Nightmare City, he would have to nourish it with countless immortal runes. Even with tens of thousands of immortal runes in the desolate world, he would still need more than a year to advance it to the level of an immortal artifact.

With Indigo Thunderwood's support, he could drastically shorten that time. It may only take him a month to upgrade Nightmare City to an immortal artifact.

Energy poured from the Indigo Thunderwood in ever-greater waves. The Indigo Thunderwood itself wasn't rare, as cultivators could commonly find it in the celestial realm, but the celestial realm's aura and laws made it precious.

Even a common tree in the Fleeting Cloud Celestial Realm wasn't something mortals could cut down, and that was why no one had managed to split the Indigo Thunderwood over the years. Liu Wuxie felt his physique pulse as it absorbed the Indigo Thunderwood's energy, and he could only probe forward since he didn't know the limits of unity with heaven and earth.

Two days later, the mysterious gate in the Outer Astral Spacetime began to tremble violently, and that single shake nearly split the Outer Astral Spacetime apart. The gate seemed to hover between reality and illusion; it wasn't tangible, yet it wasn't illusory either. No one could touch it, but it had genuinely spewed things from within.

As the crack on the Indigo Thunderwood widened, the energy rushing out surged tenfold, and the desolate world's absorption speed climbed with it. Ever since the Desolate Devouring Art had advanced to Life and Death Transformation, its devouring speed had accelerated. Evil energy in Nightmare City thinned rapidly as it gathered above Liu Wuxie's head.

Nightmare City's artifact spirit fell into stunned silence. It had never seen such a terrifying human. Even its former master, who had reached the Immortal Realm, couldn't compare to Liu Wuxie.

A person's cultivation shouldn't determine their potential. Many people reached their limit at the Heavenly Immortal Realm, while for others, it only marked the beginning.

Liu Wuxie's immortal energy continued to get purified and tempered.

"I can now try upgrading the Divine Eternal Fist to the level of an immortal art," he murmured. 𝙛𝒓𝓮𝒆𝔀𝒆𝙗𝓷𝒐𝙫𝒆𝙡.𝒄𝓸𝓶

He hadn't dared to upgrade it before, fearing he lacked enough immortal energy. However, the Indigo Thunderwood had strengthened the quality of his immortal energy by at least threefold, even though the quantity had barely increased. That was more than enough to execute the Divine Eternal Fist.

The Heavenly Dao Book began deducing the Divine Eternal Fist, and after half a day, he finally completed the deduction. It had become an immortal art he could unleash in the astral domains.

Although Liu Wuxie knew countless immortal arts, conflicting laws prevented him from using celestial-realm techniques in the astral domains. The immortal arts of the celestial realm demanded the celestial realm's laws, while the immortal arts he had used so far were born in the astral domains.

Liu Wuxie's eyes flashed as he decided to gamble. "Now that my immortal energy carries an imprint of the celestial realm's aura, will I be able to unleash the celestial realm's immortal arts?"

If he could unleash a celestial realm immortal art, even the weakest one could easily crush the Great Five Elemental Immortal Art and the Divine Eternal Fist. Then again, that wouldn't mean those two were weak, but that his foundation hadn't solidified enough yet.

An immortal art required countless years of accumulation and tempering before it could stand at the pinnacle of heaven and earth. He had cultivated these immortal arts for barely half a month, and that was nowhere near enough.

Right then, the gateway to the fourth-level Heaven Gaze Realm appeared, and he pushed the idea of practicing a celestial realm immortal art aside. He would decide again after he finished breaking through.

If he could cultivate one, he could keep it as a trump card and raise his odds if the Fleeting Cloud Celestial Realm sent someone down after him. As for using an immortal art born in the four astral domains against cultivators from the celestial realm, that was, frankly, a fantasy; immortal arts weren't just techniques, but the evolution of laws. Even the weakest immortal art from the celestial realm could easily crush the strongest immortal art in the astral domains.

Liu Wuxie steadied his mind at once and summoned the mysterious axe.