This can explain why foundation building is extremely difficult for ordinary immortal cultivators. Because their aura, although it meets the needs of foundation building, the amount of their aura is still insufficient, so the probability of failure is of course greatly increased. Unlike Nie Fei, Nie Fei's aura was frozen into ice, and the amount of aura absorbed was more than ten times more than that of ordinary people. With such an amount of spiritual energy, it is natural to break through the dam of Zhuji in one fell swoop.

Moreover, Nie Fei cultivated to the consummation of qi refining, and only realized that when he reached the consummation of qi refining, he could still absorb spiritual energy, and he did not have to build a foundation. Of course, this is not a matter of absorbing as much aura as you want. By the time the qi refining was completed and the aura was absorbed, it had already changed from moving forward.

At this time, if you absorb the aura, you will be limited by the sea of qi, which can also be said to be a kind of resistance. The more aura absorbed, the greater this resistance. In the end, it takes great perseverance to absorb a little bit of aura.

This also explains why it is so difficult for ordinary people to build a foundation. Originally, the aura broke through the barrier of building the foundation, and it was a dilemma to want to absorb more, but there were many resistances.

Ever since Nie Fei entered the Qi Refining Consummation, he felt the resistance from the sea of qi when absorbing spiritual energy. That feeling is like injecting aura into it again even though the sea of qi is already full, and every little bit of aura injected into it will make the sea of qi emit a heart-rending pain. Nie Fei tried several times, but finally couldn't stand the pain anymore and temporarily gave up the act of absorbing spiritual energy.

The reason why Nie Fei had to endure the severe pain of the sea of qi and absorb the aura into the sea of qi was not that he had to find guilt himself, there was a reason. Nie Fei had already felt that the so-called foundation building was actually the process of re-condensing the aura. In this process, the more abundant the amount of Reiki, the greater the chance of success. This process is like an inertial behavior, in the initial stage of the process, the more violent the foundation building reaction, then this reaction can be maintained until the end of the foundation building. As long as half of the aura in the body has been condensed, the foundation has been successfully built.

If this kind of foundation building reaction is not violent at the beginning, and it is not maintained at half of this critical point at all, then it is doomed to failure.

Nie Fei thought at this time, that the Zhuji Dan is likely to be an elixir that can promote the foundation building reaction, so that people can still promote the reaction when the foundation building reaction is unsustainable.

It is precisely because of the amount of aura that determines the success of foundation building, so Nie Fei is willing to endure the pain, and he must continue to absorb the aura after the qi refining is completed.

......

After Nie Fei pondered it for a day, he finally had a way to absorb the aura again after refining the qi.

When absorbing aura, the reason why the sea of qi will experience severe pain indicates that the space of the sea of qi is limited. Since the space of the sea of qi is certain, only by compressing the aura can it continue to absorb the aura.

As for compressing aura, Nie Fei has some methods.

From the next day, Nie Fei took out all the spiritual energy in the sea of qi, made it circulate in the veins, and then little by little, incorporated all these spiritual qi into the sea of qi. When incorporating into the sea of qi, Nie Fei deliberately let these spiritual qi flow through the ice spirit, passing through the center of the ice spirit. Nie Fei's idea was to use the cold aura of the ice spirit to condense the aura again.

The cold air that passed through the ice spirit condensed into ice the moment it flowed out. As more and more aura passed through the ice spirit, the ice ball condensed by the aura gradually increased. In this way, Nie Fei could be said to have compressed the aura to the maximum limit.

In fact, the aura in Nie Feiqi's sea was originally compressed, but that compression was only completed when he was close to the ice spirit, and it did not directly pass through the ice spirit. Therefore, the compression at that time was not the limit of compression, but the limit was directly through the ice.

By the time the compression was finally completed, two months had passed. Nie Fei felt the aura ice ball in the sea of qi, this ice ball was a full circle smaller than the previous aura ice ball, which meant that this time the compression of the aura was successful.

Then, Nie Fei once again absorbed the aura in the Ganfeng grass, this time the effect was very good, no matter how he absorbed it, the pain in the sea of qi never happened.

Another half a month passed. One day half a month later, Nie Fei felt that the pain of the sea of qi appeared again.

This time, Nie Fei didn't compress the aura again, because the compression last time was already the limit, even if Nie Fei recompressed it again, he could still only do this kind of thing.

"Now that the limits of compression have been reached, it's time to test my personal limits. A cold light flashed in Nie Fei's eyes, and a cold expression appeared on his face. It's just that this time the coldness is not facing the enemy, but facing himself.

Nie Fei once again made ten Ganfeng herbs into a spiritual qi medicinal liquid, and then drank it in one go, introducing the spiritual energy in it into the qi sea little by little. With the infusion of aura, the pain of the sea of qi gradually increased. But Nie Fei tried his best to hold back, still constantly absorbing aura.

In the blink of an eye, another half a month has passed. In the past half a month, Nie Fei has been tormented by the pain of the sea of qi every moment and every moment. This is really an inhuman torture, Nie Fei felt that he had survived from purgatory for half a month.

Sometimes, Nie Fei also wondered why he was suffering from this kind of torture, why did he treat himself like this? When the pain was unbearable, he also thought about giving up. But in the end, Nie Fei finally drove the urge to give up from his heart with great perseverance. No one wants to be tortured by pain, everyone is like this, and Nie Fei doesn't want to be like this. However, in order to build a successful foundation at one time, Nie Fei had to endure this pain.

Anyone who has been able to achieve extraordinary achievements must have been subjected to pain and suffering that is incomprehensible to ordinary people. Nie Fei also understands this truth, without going through some pain, if he wants to be above others, how can there be such a cheap thing in the world?

Nie Fei clenched his teeth tightly, and the majestic aura in his body spread out from his body, filling the entire cave. Even the unconscious Flying Rain felt the pressure of this aura.

Of course, Nie Fei's persistence is not blindly brute, he has a bottom line. Nie Fei's bottom line is to absorb as much aura as possible before the aura bursts the sea of qi. However, this wish, Nie Fei had to end early. When Nie Fei absorbed the aura, and when he arrived for half a year in seven days, Nie Fei could no longer absorb even a trace of aura. The intense pain made Nie Fei faint.

When Nie Fei woke up, he knew that he had reached his limit, and if he forcibly absorbed it, there would probably be a problem.

At this time, the impulse to build a foundation had completely occupied Nie Fei's sea of qi. If it weren't for Nie Fei's forcible restraint, his sea of qi would have already been baptized by the foundation building.

At this point, the preparations for building the foundation have been completed. Nie Fei said to himself: "The next step is to build the foundation." ”