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

Beginning and End had always been two sides of the same coin.

They were not two different existences.

This also meant that Beginning did not only occupy the starting point of time, but also the end of time.

This was already the extremity of the Peak Return to Void Realm, the same level as Cui Heng's current realm.

Hence, a competition in time was no longer meaningful to the two of them.

Beginning controlled time at the beginning to bring forward the final end of countless years, intending to let Cui Heng die at the hands of End.

However, Cui Heng also occupied the endpoint of time.

After sensing that the final moment of death was about to arrive, he also controlled time and delayed this end point indefinitely. Through constantly modifying the future, he made the extreme state of emptiness grow further and further away from him.

However, this situation seemed to make Beginning even happier.

Dao Integration Tribulation, Mahayana, Origin of the Dao of Immortals of Ancient Times