These eleven words had been embroidered on the white handkerchief with threads and needle.

Clearly. Nangong Wei wasn't apt in this and her embroidery was crooked. However, it was these imperfections that made Wu Yu feel her nervousness, hesitation, and uneasiness when embroidering them.

Luckily, she had decided to place this handkerchief within the Sumeru Pouch and had given it to Wu Yu. This finally allowed Wu Yu to know her real feelings.

At this instant, Wu Yu had similar feelings.

He felt that he probably wouldn't forget these words in his entire lifetime. He would not forget any stroke or the handwriting.

Through this handkerchief, he seemed to have been able to see her unwillingness to bid goodbye.

Wu Yu felt a little regretful about his actions. He acted like it wasn't a big deal when talking about the Shushan Reincarnation Realm a while ago. Nangong Wei knew more about him in this aspect. Therefore, if she felt that this would be tough and horrifying, how could it be a simple place?

If it wasn't like this, why did she have to bid goodbye and make it sound like she was giving her last words?

Wu Yu turned around abruptly and looked at the Clear Sky of Shushan. He wanted to go back and change what he told her. However, the towering Clear Sky of Shushan stopped his thoughts. This was a gap that he couldn't cross at this moment.

Nangong Wei was probably within the Shushan Immortal Domain. That was forbidden ground to even Heaven sword rank disciples. If he wanted to go there and tell her personally, it would take him at least 30 years!

It would be too late.

He placed the handkerchief back in the Sumeru Pouch and took a deep breath.

There were people who he didn't want to let down.

"Let's put this aside and leave it till we meet again." He smiled within the snowstorm. His inner heart had finally calmed down, but he had also made a decision.

Immortal Pair Hall!

That was a place that many young martial cultivators looked forward to.

One would become a heavenly couple till death do them part. That was such an alluring idea.

There were countless stories that had reached the mortal realm and were passed down for thousands of years.

"It seems like I have to quicken my pace. Otherwise, when Wei Er is back and overtakes me, I'll be really embarrassed."

His heart was determined and intense like a burning flame. This time, he had no hesitation and stepped within the boundaries of the Core Sword Cell.

The first step he had to take was to complete a certain level of metamorphosis within the Core Sword Cell in terms of realm or strength or even mentality.

Perhaps because of the legacy, Wu Yu was more fond of staves than swords. Therefore, he couldn't put down the Nine-Directional Demon Imprisonment Column. It was especially so after knowing that it represented Nangong Wei's feelings for him.

However, he still decided to hone his Jindan till he reached the third tier of the Jindan Dao Realm.

The truth was that the spiritual qi at the Core Sword Cell wasn't bad at all. Although it couldn't be compared with the thickness of the spiritual qi at Warring Immortals Hall, it was still much denser than at Futu Hall.

Wu Yu stepped into the Core Sword Cell and approached the Core Sword Tree. In just the blink of an eye, he saw a black wooden hut under the Core Sword Tree.

Wu Yu knew from the Orientation Log that within the wooden hut, there was a cell warden named Meng Fusheng. Rumor had it that he was a Earth sword rank disciple, and he was responsible for managing the Core Sword Cell. However, he almost didn't show his face at all.

When Wu Yu arrived before the wooden hut, an old and dry voice sounded from within. "Who are you and how long is your sentence?"

"Wu Yu, half a year." Wu Yu answered simply.

"Isolation cell 530. Go in by yourself. If you leave before the end of your term, your term will extend by half a year," Meng Fusheng replied.

Wu Yu knew about this. The Core Sword Cell had no guards deployed at all, and one could enter the isolation cells freely. Everything was pretty much by one's own decision. Naturally, rules were something that couldn't be defied in Shushan. Even if you were a super-talented disciple, you would still be punished.

After Wu Yu expressed his thanks, he rode on his sword and flew up. The Core Sword Tree was tall and every black fruit was an isolation cell. After reaching half the height of the Core Sword Tree and having looked around for a while, he finally found the isolation cell. It was a hollow, black fruit with only a door that could be opened for him to enter.

This fruit was known as an Inner Fruit. The interior of it was a little strange. With Wu Yu's current strength, he still found it to be completely dark after opening the door. It was just like the most silent night where one could not see anything.

For Wu Yu, this was something almost impossible.

"Rumor has it that within the Inner Fruit, there is a natural constraint on one's sight. It isn't a spiritual array, and it is hard to put it into words. It is just one of the mysterious things that occurred in the world. Within it, one's vision is completely sealed. Even if you light a flame in it, you still won't be able to see a thing. It will be as though you are blinded."

Indeed, when Wu Yu stepped in and closed the door of the Inner Fruit, it was completely silent. Not only was it completely dark where one couldn't see a thing, it was also completely quiet. Even when Wu Yu clapped his hands, he couldn't hear a thing. Therefore, the Inner Fruit robbed one of their vision and hearing.

"The Core Sword Cell is indeed an assessment of one's mental state." Wu Yu untied the Sumeru Pouch. He couldn't see the handkerchief nor the blinding Nine-Directional Demon Imprisonment Column. Moreover, the space within was smaller than he had thought. If he stood up, his head would hit the ceiling.

However, this was also a form of aid to Wu Yu.

His heart quickly settled and he recalled Nangong Wei, who was heading to the Shushan Reincarnation Realm. He instantly felt that he was definitely having a much easier path than her.

"I wonder what the Shushan Reincarnation Realm is like. Hopefully, I'll have the opportunity to go take a look in the future," Wu Yu thought to himself.

After thinking through it, he sat with his legs crossed within the Inner Fruit and started honing his Jindan with the Great Way of Immortality Art. He had started and maintained this process for seven months, and it would just be a continuation now.

"The spiritual qi in the Core Sword Cell is a little worse than the spiritual qi in Warring Immortals Hall. Things that would require three months there will require four months to achieve in this place.

"Considering this, I could possibly use Golden Essence Pills to accelerate my improvements. However, it's a shame that I have no merits left, let alone Golden Essence Pills. Poverty is still the greatest issue on the path of cultivation. Clearly, after getting out of the Core Sword Cell, I will to go earn more merits and exchange them for my resources!"

Wu Yu still maintained a clear mind. Nangong Wei's status was high and noble. There would be many things that wouldn't go as they wished. If they hoped to take a further step forward, Wu Yu felt that his talents were his strongest support.

"Calm down and focus on the present."

The Core Sword Cell was a place solely meant for this. It enabled one to be unbelievably calm. One's thoughts could thus become clear.

"Rumor has it that there are many people who volunteered to enter the Core Sword Cell to achieve dao enlightenment!"

It was especially so for refining one's Jindan. The idea was similar to smelting iron, which required constant hammering and thumping to condense the Jindan to an extremely small size. In order to condense horrifying powers into it, it would require nonstop polishing!

Spiritual qi was the fire, the Jindan Condensation Wondrous Art was equivalent to the hammer, and Wu Yu would be the blacksmith. He had the best hammer in the world to refine his Jindan!

When he got into the rhythm of things, the sense of time passing gradually faded. His time in the Core Sword Cell passed by much faster than he had imagined.

As time passed by, Wu Yu would occasionally think about what Nangong Wei might be facing in the Shushan Reincarnation Realm and what kind of improvements she had made...

Such longing thoughts were, in fact, pretty interesting. In the short run, cultivation would not only extend his longevity, but also gave him a strong desire to achieve his goal!

He controlled his rhythm well, and soon, approximately four months had passed. His Jindan had finally reached a new level. His Jindan essence surged and he reached the third tier of the Jindan Dao Realm. He was getting closer and closer to the fifth tier, where he would become one with the Jindan.

His white Jindan exhibited even more domineering might at the new tier. The surface was covered by dense, white fog like a miniature immortal realm.

The white fog was constantly swirling with mysterious, complex symbols emblazoned upon it.

"The Jindan Dao Realm is much deeper and mysterious compared to the Qi Condensation Realm."

Wu Yu continued his refining. After stabilizing his tier, he formed some observations.

"For the first three tiers of the Jindan Dao Realm, one's actions are mainly mechanical and a huge amount of time is necessary to refine it. However, from the fourth tier and fifth tier onwards, simple, mechanical refining won't suffice. Sometimes, it will require some enlightenment, and one will have to achieve communion with the heavens and earth. Only then would it be more effective in refining the Jindan. Otherwise, one would find that no matter how he refined it, his Jindan would not get stronger. In fact, it might just stagnate and Golden Essence Pills will be useless.

"For example, the fourth tier of the Jindan Dao Realm is about achieving enlightenment of the heavens and earth to adjust to the changes on the surface of the Jindan. This will include absorbing and combining more spiritual qi. The deeper one's enlightenment is, the quicker the refining of Jindan will be."

“For the fifth tier of Jindan Dao, one has to become one with the Jindan before being able to graft a Great Dao Mystique on it. This allows one to gain battle techniques that are more powerful than dao techniques.

"As for the sixth tier of Jindan Dao and above, it will be even more complicated."

The Qi Condensation Realm required a certain level of talent. With sufficient time to condense one's spiritual source, one can definitely reach the Jindan Dao Realm. For the first three tiers of Jindan Dao, even one with the worst Jindan Condensation Wondrous Art could improve by refining one's Jindan repetitively over dozens of years. However, if one was to advance further, one's thoughts and sensitivity to enlightenment would play a bigger part. In fact, the importance was even greater than the effects of Jindan Condensation Wondrous Art.

Many geniuses might be advancing slowly before the third tier of Jindan Dao. However, once they reached the fourth tier of Jindan Dao, with their exceptional sensitivity to enlightenment, their pace of improvement would get quicker and quicker. At that time, the most important quality of a person would be his heart.

Using one's heart to gain enlightenment from the heavens and earth and to approach the illusory dao within the heaven and earth before reflecting it on one's Jindan. A Jindan wasn't simply the combination of Jindan essence and immortal fire. It was the crystallization of one's dao.

Rumor has it that refining immortal medicines or fashioning spirit designs and arrays increases one's mental realm and one's sensitivity to thoughts.

After all, refining immortal medicines was a test of application of immortal fire, the dissection of complicated steps, and detailed control of fine areas. Spirit designs would be even more complicated and require an even larger concentration and detailed control.

"Disregarding the fourth tier, I can still use a large amount of Golden Essence Pills to refine my Jindan directly at the third tier. Only when I have broken through to the fourth tier do I need that kind of sensitivity to enlightenment.

"However, I have to earn my Golden Essence Pills while still having to remain in the Core Sword Cell for another two months.

“Over this period of time, let's get used to the Nine-Directional Demon Imprisonment Column first!"

Up to this point, Wu Yu had not formed a blood bond with the Nine-Directional Demon Imprisonment Column.

The Paranormal Pillar of Blood was initially the weapon of ghostly cultivators. Wu Yu gave the idea up directly. That wasn't suitable for his mental state. If overused, it would increase his desire to kill.

Within the extreme darkness, he could no longer see the looks of the Nine-Directional Demon Imprisonment Column.

However, he still could sense the arrogance and violent spirit of the Nine-Directional Demon Imprisonment Column. Spiritual immortal treasures possess spiritual affinity. They were similar to small beasts. Therefore, when Wu Yu wanted to form a blood bond with it, it was also a form of taming.

Just as Wu Yu had expected, it wasn't easy to tame a fierce beast!

Even the Yin Yang Dao Sword had not resisted Wu Yu. However, the Nine-Directional Demon Imprisonment Column was resisting Wu Yu like a ferocious beast!