Nie Li took out the Nightmarish Demon Bottle.

This pitch-black jade urn shimmered with a faint glow, emanating a mysterious aura.

This item was an ancient treasure, and Nie Li was astonished to find it at an auction house.

Without hesitation, he bid for it, knowing that if he missed out on the Nightmarish Demon Bottle, he would surely regret it.

With his right hand, Nie Li gently caressed the Nightmarish Demon Bottle and infused a strand of soul force into it.

Suddenly, the bottle burst forth with brilliant light, establishing an inexplicable connection with Nie Li.

He only understood a fraction of its capabilities and had much more to explore.

One of the functions of the Nightmarish Demon Bottle was that if ten demon spirits of the same attribute were refined together, there was a certain chance of forging a more powerful demon spirit.

Of course, there was also the possibility of failure.

Nie Li had purchased so many demon spirits precisely to conjure a more potent one!

"I already have an assassin-type demon spirit, but what I urgently need now is a berserker-type demon spirit that can confront opponents directly!" After pondering, Nie Li realized he had bought over two thousand berserker demon spirits.

He hoped at least one would evolve into a powerful berserker spirit.

Each demon spirit was categorized by its soul strength before its demise, falling into ranks of bronze, silver, gold, black gold, legendary, and more, which was the standard of Glory City.

Ordinary people did not realize that the growth potential of each demon spirit varied greatly.

Even lower-level spirits, if they had strong growth potential, could eventually defeat legendary spirits!

Moreover, some special demon spirits had growth potential that far exceeded that of ordinary ones, like Nie Li's Shadow Demon Spirit!

Nie Li classified the growth potential of demon spirits into five levels: Inferior, Average, Good, Excellent, and Extraordinary, with divine being the highest.

The Shadow Demon Spirit undoubtedly possessed divine-level growth potential, and its strength had no upper limit.

Ordinary people were clueless about how to distinguish the growth potential of demon spirits.

Only Nie Li understood that, similar to testing soul force in humans, the growth potential of demon spirits could also be measured using soul crystals, though the method of assessment differed.

The second demon spirit to be fused would have a significant impact, so Nie Li needed to choose carefully.

Even if he couldn't obtain a divine-level spirit, at the very least, he wanted an extraordinary one; otherwise, it would be too much of a waste for the pricey Nightmarish Demon Bottle!

Nie Li took out ten demon spirit stones and tested the levels of these ten spirits with a soul crystal.

"Scattered soul cloud, inferior level spirit!"

"Fragmented soul cloud, average level spirit!"

...

Nie Li quickly checked the ten spirits, discovering seven were inferior and three were average.

He couldn't help but feel a bit disappointed.

"It really is challenging to pick out higher growth potential spirits from mere average ones!" he thought, feeling somewhat frustrated.

Finding a divine-growth potential spirit like his Shadow Demon Spirit was indeed a tough task.

Otherwise, he wouldn’t have risked entering the Ancient Orchid City Ruins.

However, these demon spirits, which Nie Li deemed useless, would be revered as treasures by ordinary folks.

He placed these ten spirits into the Nightmarish Demon Bottle and activated it with his soul force! Immediately, the bottle shimmered with dazzling lights, exuding brilliant hues, as ghostly auras flowed inside.

Nie Li watched as ten streams of light continually spun together before gradually merging into a thick mist.

About ten minutes later, the radiance of the Nightmarish Demon Bottle began to calm.

A demon spirit emerged within, gliding around like a sprite at the bottom of the bottle.

Nie Li captured the spirit and attached it to an ordinary demon spirit stone, then examined its growth potential.

"Slightly complete soul cloud, already at a good level! The Nightmarish Demon Bottle is indeed extraordinary! But a good-level spirit is still not enough!" Nie Li shook his head; his standards were too high to settle for anything less than good.

Setting aside this good-level spirit, he took out another ten demon spirit stones for testing.

Among the ten berserker spirits, the best was only a good-level bull demon spirit.

Nie Li fused again and again.

Success!

Failure!

...

The failure rate was still quite low, showing up only once in dozens of attempts.

After over sixty trials, the best result was an excellent-level berserker spirit, while the rest were good-levels.

"This won't do!" Nie Li shook his head; it was challenging to upgrade these lower-tier spirits.

Nevertheless, with so many spirits at his disposal, he wouldn’t give up on refining them.

From the two thousand spirits, he would definitely get several excellent-level berserker spirits, totaling over sixty good-level ones, which was quite decent since some spirits had relatively high growth potential.

Over two days, Nie Li kept refining, merging inferior and average spirits into good ones, then using these good spirits to create excellent ones.

Eventually, he ended up with over ninety excellent spirits, which he could then fuse into extraordinary-level ones.

As he ascended the ranks, the failure rate increased.

Ultimately, he succeeded in fusing five extraordinary-level spirits.

Looking at these five extraordinary spirits, Nie Li still felt unsatisfied.

It required ten extraordinary spirits to have even a chance of fusing a divine-level spirit, and the chance of failure was very high.

When fusing extraordinary spirits, the success rate was only fifty percent, while attempting for a divine spirit had only a one in five chance of success.

The Alchemist Association had recently sent him their accumulated earnings, totaling nearly one billion demon spirit coins.

After some deliberation, Nie Li went to see Nie Hai and Nie En, enlisting their help to buy as many berserker spirits as possible.

They would earn a reward for every berserker spirit they acquired.

The compensation Nie Li offered was generous, so they obviously gave their all.

Soon, Nie Hai and Nie En hustled among various guilds, and after spending billions, Nie Li successfully bought thousands of berserker spirits and began fervently using the Nightmarish Demon Bottle.

As the fusion attempts increased, Nie Li noticed significant changes in the Nightmarish Demon Bottle.

Originally muddled, it became remarkably clear, allowing him to see the merging process of the demon spirits within.

Nie Li's heart tightened; he sensed that the Nightmarish Demon Bottle could absorb a part of the spirits' power during the fusion process.

Over time, the bottle would grow even more potent.

(End of Chapter)