So here's the question: why would Uchiha Kō have such a dream? And the original work doesn't mention anything about Qing Xiao, Yun Shou, or Ruan Yu, so how did he encounter so many things after transmigrating here?
"System, could you explain in detail?" Uchiha Kō asked seriously, understanding that this matter was extremely important!
The system sensed that Ruan Yu in this world had been resurrected, and helplessly, it could only say, "The dream you had was caused by everything from your past life. And my origin is closely related to your past life."
After speaking, the system materialized, transforming into the appearance of Qing Xiao in Uchiha Kō's dream. Uchiha Kō stared in astonishment at the appearance of the Mental Space system: "You, you are!"
"That's right, I am you. To be precise, I am just a remnant soul from your past life."
"I'll answer your next question." After saying that, the system paused time, then sat down on the ground, touching its forehead, its eyes filled with reminiscence.
"Listen to me..."
Qing Xiao is the strongest male cultivator in the cultivation world, while Ruan Yu is the strongest female cultivator. Cultivators all believe that Qing Xiao and Ruan Yu are a perfect couple and will eventually become husband and wife.
However, the appearance of Yun Shou shattered everyone's expectations. Yun Shou appeared out of nowhere in the cultivation world, cultivated for a hundred years as a mortal, and achieved the status of Immortal Venerable. This was inseparable from the support of Immortal Venerable Qing Xiao.
Ruan Yu had always secretly loved Qing Xiao, but there were only two immortals in the world, and this had been the case for tens of thousands of years. Therefore, Ruan Yu believed that sooner or later, Qing Xiao would understand that the two of them were a match made in heaven.
However, after Yun Shou became an Immortal Venerable, Qing Xiao fell in love with him, which made Yun Shou Ruan Yu, who had waited for tens of thousands of years, feel resentful. From then on, Ruan Yu severed all love and prepared to break through to a stronger realm, Immortal Emperor.
Ruan Yu's talent has always been recognized as the best in the world. After severing all emotions and love, her cultivation level increased significantly. When she broke through to the Immortal Emperor level, she was challenged by the Heavenly Dao. She could easily handle the first few questions until the last one.
"Do you still harbor any obsessions?" The voice of Heavenly Dao carried an air of authority.
Ruan Yu was silent for three seconds, then said, "No." The next moment, Ruan Yu spat out a mouthful of blood—a demon within her! This was a demon buried deep within Ruan Yu's heart!
The Heavenly Dao sighed, "A Celestial Emperor must rid himself of the seven emotions and six desires in order to attain the Dao and wield the power of life and death in the cultivation world. Ruan Yu, what a pity."
After saying this, the Heavenly Dao departed, and Ruan Yu failed to attain enlightenment, her cultivation completely dissipated. Qing Xiao showed reluctance at the time, so he met with Ruan Yu in private and gave her the cultivation resources he had accumulated over the years.
After all, we were all outstanding figures of our time; how could we stand idly by when the other fell on hard times?
Although Ruan Yu had lost all her cultivation, she still possessed the demeanor of a Celestial Venerable.
She cupped her hands to Qing Xiao shook his head and turned to leave. But when Ruan Yu looked up, her gaze fell on Qing Xiao, and the clarity in her eyes suddenly turned into madness.
After Qing Xiao left the mansion, she saw Yun Shou appear, put his arm around Qing Xiao's arm, and the two left chatting and laughing.
Ruan Yu's obsession grew heavier and heavier; she wanted Qing Xiao! Even if it meant possessing him! Even if it meant being rejected by Qing Xiao!
But before that, she needs to cultivate!
Three thousand years passed in the world of cultivation, and Qing Xiao and Yun Shou traveled around, enjoying all the flavors of the world.
Ruan Yu became possessed by a demon and devoted herself to arduous cultivation. In the end, she used her obsession to become the Demon Emperor. The first thing she did after becoming the Demon Emperor was to take Qing Xiao for herself!
She used all living beings to force Qing Xiao to reveal himself. Qing Xiao had no choice but to step forward and try to persuade his friend to return to the right path.
Hearing Qing Xiao's words, Ruan Yu smiled. Her smile was beautiful, lacking any of the demon's ferocity, but possessing a touch of allure. She said, "Sure, if you marry me, I will only listen to you from now on. With you by my side, I will not kill innocent people indiscriminately. How about it?"
Qing Xiao frowned, then shook his head and refused. "I'm sorry, Ruan Yu, love can't be forced. Please let go of your obsession!"
Ruan Yu remained silent, then sneered, "Is it because of Yun Shou?" Her laughter was filled with desolation. She hadn't expected that her nearly fifty million years of friendship with Qing Xiao would be less than a few hundred years with a little girl.
Qing Xiao shook his head. "This has nothing to do with Yun Shou."
Ruan Yu, however, revealed her murderous intent. "Qing Xiao, don't you think you're being too cruel to me?" Her eyes reddened, and tears were about to fall, but Qing Xiao remained expressionless. Feelings are irrational.
Ruan Yu shed a tear, then turned around, using her demonic power to lock onto Yun Shou's location, her face filled with murderous intent. As long as she killed Yun Shou, Qing Xiao would change his mind!
She set off, and Qing Xiao, sensing the direction she was heading, changed his expression drastically and gave chase.
Thus, two against one, Yun Shou and Qing Xiao fought together against Ruan Yu who had become possessed by demons. The three were evenly matched, and in order not to harm the innocent, Qing Xiao suggested going to other worlds.
Ruan Yu's goal was to obtain Qing Xiao and kill Yun Shou, so naturally, he couldn't refuse. Thus, the three of them descended into Hokage world, which at that time was still uncivilized and inhabited by races whose intelligence was not yet fully developed.
The three fought fiercely here. Perhaps because Qing Xiao was lucky, this world restricted their cultivation levels, causing Ruan Yu, Qing Xiao, and Yun Shou to all reach the same cultivation level.
However, Ruan Yu was originally the strongest in the world, and after becoming a demon, she completely surpassed Qing Xiao. She could fight two opponents at once without being at a disadvantage. She held back against Qing Xiao, but was ruthless and decisive against Yun Shou.
And so, the three fought for five hundred years. During this time, the human race also appeared. The Ōtsutsuki Clan sensed the power of the three and were very curious, but also very wary. They did not participate and instead observed everything from the clouds.
Finally, Ruan Yu found an opportunity and struck Yun Shou on the top of the head with a palm. Yun Shou was knocked down by this palm. Qing Xiao roared, "Yun Shou!" Then he briefly unleashed a power that transcended the world plane.
Ruan Yu killed Yun Shou, which should have been a happy event, but seeing Qing Xiao unleash his power for her sake, burning his soul to kill her, broke her heart.
She did not resist, fearing that if she did, Qing Xiao would consume too much of his soul power and dissipate into the vast world, driving her mad.
Thus, Ruan Yu was sealed in a coffin by Qing Xiao using the technique of severing the connection between heaven and earth, without any regrets.
Before being sealed away, she said, "Xiao, I've actually loved you since I was sixteen, for a full fifty thousand years." After saying that, she pushed Qing Xiao away and walked into the coffin herself, lying down.
Her eyes held both love and sadness, but that's how love is; it doesn't mean that just because you like someone, it will have a happy ending.
Upon hearing Ruan Yu's words, Qing Xiao roared. The sound of his roar caused the Otsutsuki on the cloud to tremble in fear; the power was terrifying!
In an instant, a torrential rain fell from the sky. In this small world, a Celestial Venerable died, and a Demon Emperor was sealed away. The immense karma separated this world from the timeline that originally belonged exclusively to Hokage.
Qing Xiao collected Yun Shou's soul. Due to the long time that had passed, Yun Shou's soul had become integrated with this world and could no longer return to the cultivation world. Therefore, Qing Xiao used his great supernatural powers to allow her to live on in this world.
Having exhausted his immortal power, he was unable to return to the cultivation world. This world had no spiritual energy and no immortal power, so he could only grow old and die in this world.
However, he left himself a backup plan: to have a wisp of his own soul search for his reincarnation and to allow his reincarnation to continue his previous relationship with Yun Shou's reincarnation.
Over the course of thousands of years, his remnant soul wandered this world, learning about chakra and ninjutsu, and recording all the people, events, ninjutsu, and Taijutsu he encountered.
After sensing the soul fluctuations of the original body, he resolutely broke through the space-time barrier and came to the 21st century. After seeing the original body, he directly entered its body, brought it to this world, and used powerful means to make its identity reasonable.
That concludes the information about the previous lives of Uchiha Kō and Tsunade!
Uchiha Kō's expression was complicated. "I said, how could you be such a heartless man?"
Qing Xiao remained silent, glancing at the original body. "Please watch your words. I am a remnant soul, you are the original body!!!"
Qing Xiao rolled his eyes; he was truly speechless!
Uchiha Kō shook his head. "I don't believe in past lives or reincarnation. I only know that my greatest love is Tsunade. As for the past life, it ended after my death! Anyway, I don't admit that I did it!"
Qing Xiao sneered, "Oh~ It's alright, it doesn't matter if you don't admit it. Ruan Yu just came back to life, and you two will have to settle this ill-fated relationship sooner or later."
Although Qing Xiao is a remnant soul at this moment, it is still a wisp of Qing Xiao's obsession. Besides completing the task with Yun Shou's reincarnation, it is also about Ruan Yu.
Although he didn't like Ruan Yu, Yun Shou died because of him, and Ruan Yu became possessed by a demon because of him. He couldn't solve the problem, so he wanted to solve it in his next life. He wanted to use this to sever ties with her.
Regardless of the outcome, once these matters are resolved, Qing Xiao's obsession will dissipate, and all his techniques and memories will be injected into the present-day Uchiha Kō.
Whether Uchiha Kō admits it or not, he is the reincarnation of Qing Xiao Venerable!
Uchiha Kō immediately broke out in a cold sweat. "Damn it, Qing Xiao is so unreliable! This bastard is unbelievable!" What kind of mess is this?! He can't handle this mess himself, so he'll leave it for the next life! Qing Xiao even human?
Oh, right, he's not human, he's a celestial being!
After Qing Xiao saw that Uchiha Kō had finished accepting the remnant soul, he said, "I have stopped time for an hour, and it has consumed a lot of energy. I need to sleep during this time, so don't wake me unless it is a life-or-death crisis!"
After speaking, Qing Xiao transformed back into the history panel, returning to the state he was in after being attacked by this Heavenly Dao. He was cold and aloof, and then time began to flow again.
Uchiha Kō's consciousness returned to reality. He looked at Tsunade and saw Tsunade worried expression. He smiled and said, "Wife, don't worry, it was just a nightmare, it's all fake."