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

"It's an invitation to the Immortal Heavenly Dao Realm Dharma Banquet!" The eyes of the Human Monarch's descendant lit up when he saw the invitation. "You were actually once covered by the Six Immortal Domains?" Under normal circumstances, only those who cultivated under the scope of the Six Immortal Domains would receive an invitation to the Immortal Heavenly Dao Realm Dharma Banquet.

"This isn't an invitation that appeared naturally." Cui Heng shook his head and said, "It was Daoist Su who invited me."

"Daoist Su?!" The Human Monarch's descendant's eyes widened when he heard this. His expression changed completely as he said in shock, "It's actually an invitation from that otherworldly expert!"

After learning this, the way he looked at Cui Heng changed again. It actually changed from fear to admiration.

Meeting at the Dharma Banquet, Immortal Technique to See through Illusions (2)