Lin Xuan had already preliminarily mastered the use of the blue light point, but whether this was all its secret, or just the tip of the iceberg, Lin Xuan decided to continue exploring.

Pour out a pill from the jade bottle, this is not a waste pill, but a good marrow cleansing pill, which was obtained from Zhou Yan.

Waste pill can be purified, so can the next grade marrow washing pill also be further purified and upgraded?

Lin Xuan wanted to give it a try!

It is important to know that the Dao of the Sect, including the Purifying Pill, each elixir in the cultivation realm is divided into four grades: lower grade, middle grade, upper grade, and best grade.

The elixir is graded, in fact, it mainly depends on the impurities contained in it, there is no difference in the material, the more impurities, the more dispersed the useful essence, and the worse the effect after taking it.

On the contrary, high-grade pills have fewer impurities and concentrated essences, and the more obvious the effect after taking it.

Of course, the higher the grade of the elixir, the more difficult it is to refine.

Generally speaking, the impurity content of more than 70% is called waste pill, the impurity content of the lower grade pill is about 50 percent, the middle grade is 30 percent, and the upper grade is 10 percent, while the impurities in the best pill are very few, only 23 percent.

The cultivation realm has been trying to reduce the impurities of the pill for tens of thousands of years, but countless grandmasters, clever and talented people, have worked hard, but the harvest is very small, and now the various elixirs in the cultivation realm, such as the Washing Pill, Zhuji Pill, Peiyuan Pill, Nine Turning Pill, etc., are mostly of the lower grades.

Lin Xuan now wants to try to go further, since Xinghai can purify the waste pill into a lower grade, can it also purify the lower grade pill into a medium grade?

Theoretically, it should be possible, Lin Xuan sat down cross-legged, holding a snow-white pill in his hand, and the blue light spots in the dantian were gathered.

After more than a month of practice, especially after breaking through the second layer of the agility period, the skill has increased greatly, and the blue light point is no longer jerky anymore.

But Lin Xuan was not careless, what he wanted to do today was a new attempt, he released all his divine sense, flowing in the meridians with the points of light, and then all concentrated on the marrow cleansing pill in his hand.

After entering the second layer of the Spirit Period, Lin Xuan's values in all aspects were increasing exponentially, in addition to spiritual power, his divine sense had also been enhanced to a great extent, originally he could only observe the changes on the surface of the Cleansing Pill, but now he could penetrate into the interior of the pill.

Originally, from the outside, it was snow-white, but at this time, Lin Xuan found that there was still a trace of black inside, which was entangled with the white part, that is, impurities.

What we need to do is to get rid of these useless things.

The blue light passed through the skin and entered the inside of the elixir, Lin Xuan had no way to observe this process before, all he could do was control the speed of the blue light flow.

And now, the divine consciousness has been enhanced, and it can enter the inside of the elixir, and the specific situation of purification can be further studied.

Lin Xuan controlled the speed of the flow of light points while observing carefully.

I saw that after the light point enters the elixir, it flows inside, white represents the essence, black represents the impurities, when it encounters the essence part, the blue light will pass directly through it, without any barrier, and when it encounters impurities, it will be pushed outward a little, and in this process, the blue light will also consume energy.

Lin Xuan saw a black impurity with his own eyes, and every time he encountered a blue point of light, he moved forward for a short distance until he was pushed out of the pill, so that the impurity was reduced a little.

It turned out that the purification process was like this, Lin Xuan nodded in his heart, and his understanding and mastery of blue light was a little deeper.

"Since the divine consciousness can enter the inside of the elixir, can the blue light spots inside be controlled?" Lin Xuan had another idea, because the flow of light spots in the elixir was chaotic, and the purification efficiency was not high, if he could control it and gather them together, then the purification would become easier.

Lin Xuan began to try.

In order to control the points of light that overflow from the body, it is necessary to attach the divine consciousness to it, and the principle is not difficult, similar to the exorcism, but it is difficult to do.

Unlike actual objects, the point of light is incorporeal and formless, if it is a high-level cultivator, it can also be controlled, but Lin Xuan's cultivation is only the second layer of the spirit stage, although the divine sense is much stronger than before breaking through the bottleneck, it is still far from enough.

With all his efforts, it only made the blue light tremble.

Lin Xuan wisely chose to give up, it was too reluctant now, and he would try again after his cultivation realm improved.

As a result, Lin Xuan refocused his attention and divine sense on controlling the flow speed of the sea of stars in his body, and continued to purify.

This process was not all smooth sailing, and soon encountered new problems, compared with the waste pill, although the impurities in the lower pindan are less, they can be more closely entangled with the essence part, that is, in order to separate them, more blue light energy needs to be consumed.

And as time passed, after an hour, the sea of stars in the dantian had shrunk to one-third of its original size, approaching the warning line, and it was no longer possible to output blue light outward.

After the blue light stagnated, the impurities that had been about to be expelled from the elixir rebounded back, returned to their original state, and were more closely integrated with the essence.

The pill also changed from pure white to light black.

Lin Xuan opened his eyes and looked at the scrapped pill in his hand, with a thoughtful expression on his face, although this time the test was not successful, it also had a lot of gains.

First of all, his divine consciousness can enter the inside of the elixir, and he has a certain understanding of the purification process, which is immeasurable for better mastering blue light.

Second, the blue light that enters the inside of the pill can still be controlled, but now his own skill is not enough, and when his divine sense is strong enough, the flow of blue light in the pill will be controlled, and the purification efficiency will be higher.

The so-called experience is to accumulate in the attempt, in addition to practice, but also need to be good at summarizing, Lin Xuan every time he does a test, whether it is success or failure, he will analyze it in depth.

It is precisely because of his attitude, coupled with his boldness and carefulness, that he gradually discovered the secret of the blue light point from the original ignorance, and mastered it more and more, and went deeper and deeper.