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

During this process, his understanding of death quickly became clear. There was even a world formed by the concept of death that formed in his mind bit by bit. This allowed Cui Heng to understand something.

"After I comprehend death completely, the death of this universe should have a home."

In the Myriad Heavens Palace in the Primordial World.

The four Heaven Lords had already gathered, and Han Shenyi was among them. He looked at the person in charge of the region who was kneeling on the ground and trembling with a dark expression.

After some investigation, the Myriad Heavens Palace quickly found the information that Fang Jian had deliberately hidden.

Immortal King Haojun's fragment soul had been killed in the Lower Realm.

In order to express their disdain for the Chaos Universe, the experts of the Primordial World would usually call it the Lower Realm.

Origin of Death, 480 Million False Selves (2)