Sole Cloud Flying Cave

Cui Heng was transmigrated to another world and the system told him that the new world he was in was a high-grade Xianxia world.
It was a world where Celestial Kings soared the sky and terrifying monsters ruled the lands. The strong would destroy a planet if their mood was bad and Cui Heng trembled in fear when he learned of how scary the new world was.
Thankfully, the system had granted him the protection that last for 300 years. As long as he remained in the safety zone, he would not receive any damage.
With his safety secured, he began his cultivation training for the next 300 years.
Throughout the years as he trained, some people entered his safety zone by mistake.
There was a peasant who was once a monk and a beggar. Despite that, he still had the dream of bringing peace to the land and saving the lives of millions.
There was a noble who was once called the once-in-a-million-year genius. Yet, luck wasn't at his side and his talent fell and was laughed at by others for years.
There was a princess whose only wish was to find her older brother. She could've become a celestial but decided to remain in the human realm to wait for her brother's return.
There was a weak lady who was plagued with illness from birth but had the goal of adventuring and helping the poor and weak.
...
Cui Heng befriended these people and even gave them a few pointers before they left.
300 years later, when the protection period had ended, he had finally mastered the Golden Core. Even then, he was still reluctant to go to the outside world.
But when he did, he realized that the world was merely a world of Wuxia.

Realizing This Is A Wuxia World After Cultivating For 300 Years

"As long as a Quasi Immortal Emperor or Heaven's Will who has grasped the power of Heaven Heart Light takes action, they will definitely not be able to escape the surveillance of the Lost Water Treasure Mirror. At that time, it will be obvious if the laws of the Boundless Chaos Sea have weakened." "Master is far-sighted." Yan Qing cupped his hands and smiled. "Junior Brother Feng also has an important mission this time."

"When he returns, I'll reward him well." Emperor Wu smiled.

While the two of them were discussing happily, they had no idea that Feng Sheng had already fallen to the Dao Heaven Realm, from an Invincible Immortal King to an ordinary Immortal Monarch.

In fact, just as Emperor Wu and Yan Qing were about to monitor the changes in the laws and River of Time in the Boundless Chaos Sea, Cui Heng had already begun to pry into Feng Sheng's past.

The Strange Movement in the Boundless Chaos Sea, The Sun on the River of Time (2)