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[Old Li wasn't surprised that you knew about this formation.]
[After all, Senior Lu Wuya had left a formation in the belly of Ridge Mountain. Most cultivators here knew about it. It wasn't a secret.]
[For this reason, people guarded the formation every day, fearing that immortal slaves would secretly destroy it.]
[After hearing your request, Old Li thought for a moment and then took you there personally.]
[You successfully entered the belly of Ridge Mountain and came to the formation left by Senior Lu Wuya.]
[In the following days, you continued to observe and study this formation through various formation knowledge.]
[But apart from feeling dizzy, you gained nothing. You knew you were anxious.]
[With your current attainments in formation, this formation was like a wordless book of heaven for you.]
[The principle of the formation was to use various basic formation symbols to form different combinations to achieve different effects!]
[You couldn't even see the most basic array symbols for setting up the array, let alone learn them.]
[You knew this was because your array attainments were too low. After the array symbols were combined, they were too complicated. You couldn't understand them, so you couldn't see them.]
[So you had to leave, and you decided to wait until your array attainments improved before coming back.]
[During this time, Mr. Li followed you closely.]
[You knew this was because the array left by Senior Lu Wuya was too important, and Mr. Li might not fully trust you.]
[In the seventeenth year, you retreated again and studied the array honestly; for this, you even temporarily gave up the practice of immortal martial arts.]
[As for the reason, you knew that Senior Lu Wuya's array would not last until the next time the thunder fell, and it would collapse.]
[You wanted to improve the array with all your strength and try to repair it.]
[You thought that as long as you could repair the array, you could hide in it after the thunder fell in the future, so that the simulation time could be extended!]
[And this time you also had the talent of living longer than Nanshan Mountain, which increased your lifespan by a thousand years.]
[As long as you could repair this formation, you could practice for thousands of years. You thought this was a great benefit.]
[In the twenty-third year, you successfully set up a medium-grade spirit gathering formation and became a fourth-grade formation master.]
[At this time, you finally understood that the formation was not as easy to break through as you had thought.]
[After digesting the formation jade slip, it took you a full six years to upgrade one level.]
[And when Mr. Li learned about this, he was even more excited than you.]
[He asked you if you still wanted to observe the formation left by Senior Lu Wuya.]
[You were a little confused.]
[Until the end, Mr. Li asked you to help Jibei Mountain set up more medium-grade spirit gathering formations.]
[You realized that he was asking you to do something!]
[Thinking back, you thought this was normal.]
[After all, the people who practiced here generally used primary spirit gathering formations.]
[As for the reason, it was also simple. Few of the immortal cultivators in the Back Mountain had the talent for formations, and even ordinary formation masters had rarely appeared.]
[They could only set up a primary spirit gathering formation.]
[You had heard that there used to be an advanced spirit gathering formation, but it was old, dilapidated and ineffective.]
[The spiritual energy here was originally thin, and there was no good spirit gathering formation. This was why the immortal cultivators in the Back Mountain often organized people to rob the spirit stones of the Immortal Spirit Gate.]
[After all, it was too difficult for them to practice here. Even if they had the talent for immortal cultivation, it was useless without spiritual energy.]
[You agreed to Mr. Li's request without hesitation.]
[In the twenty-fourth year, you spent a whole year setting up hundreds of intermediate spirit gathering formations in Ridge Mountain.]
[This strengthened your understanding of formations.]
[And what you did was also appreciated by many immortal cultivators in Ridge Mountain, who gave you spirit stones as a thank you gift.]
[Although there weren't many spirit stones here, thousands of immortal cultivators each gave a little thank you gift, and all added up, you also received 580,000 spirit stones.]
[This was already a huge sum of money for you.]
[In the thirty-first year, you successfully broke through to fifth-grade formation master.]
[In the thirty-ninth year, you reached sixth-grade formation master.]
[After that, you felt that your formation skills progressed much slower.]
[But you didn't feel strange. After all, if you were given time to set up formations, a sixth-grade formation master could already rival an immortal cultivator in the Refining Void Realm.]
[If you could continue to progress at this high speed, wouldn't your formation skills be invincible?]
[In the 40th year, you once again entered the belly of Ridge Mountain and came to the formation left by Senior Lu Wuya.]
[This time, you could barely see some of the formation symbols in the formation.]
[This opened your eyes. You roughly estimated that there were millions of formation symbols that you could see.]
[These runes intertwined, forming various combinations of formation symbols, interweaving with each other.]
[For a moment, you were a little dazzled.]
[And what you could see was only part of the formation, and there was still a large part that you still couldn't see clearly.]
[You estimated that this formation must have at least hundreds of millions of formation symbols.]
[This was simply unimaginable.]
[Hundreds of millions of formation symbols, how many combinations of formation symbols must there be.]
[You had now reached sixth-grade formation master, but the formation you could set up only required tens of thousands of formation symbols, and the combination of formation symbols you used was only a hundred or so.]
[Even so, in the eyes of Mr. Li and others, you were already a very powerful formation master.]
[You dared not imagine how powerful Senior Lu Wuya must have been.]
[Of course, what worried you more was the forbidden formation outside the South Region.]
[The formation left by Senior Lu Wuya used so many formation runes, how powerful would the formation that could block the entire South Region be.]
[When you thought of this, you couldn't help but feel a little desperate.]
[Soon, you kept reminding yourself that this was a simulation and you still had time to improve.]
[You concentrated your mind and carefully observed the formation runes you could see, to study their patterns and their operating principles.]
[A day later, you had a splitting headache.]
[Obviously, this was because your current attainments in formations could not easily understand the patterns of the large number of runes in this formation.]
[This formation was still too complicated for you now.]
[Then you could only leave this place.]
[However, one day of research still benefited you a lot.]
[You knew a lot of different array symbol combinations. If you could study those array symbol combinations, perhaps your array attainments could be greatly improved!]
[In the 41st year, you triggered a chance epiphany, and gained a 10-fold increase in cultivation speed, and your thinking became more active.]
[This epiphany lasted for a full ten months, and you broke through to seventh-grade array master in one fell swoop.]
[At this time, your array attainments had actually far exceeded your cultivation level. A seventh-grade array master, if compared with a cultivator, could be regarded as a great power in the fusion period.]