i have immortality in the cultivation world

When Zhou Yi woke up, he realized that he had become the prison guard of the Heaven Dungeon.
Although he was fortunate enough to find a Fruit of Eternal Life, he did not possess any powers to protect himself.
In a world of cultivation where demons and monsters roamed freely, Zhou Yi decided to hide himself and train for thousands of years.
Time passed by quickly.
The child he had freed 100 years ago had become the founder of the Great Qian Empire.
The teenager he had helped 1000 years ago had become the elder of a celestial sect.
The pet he had kept 10000 years ago had become the Absolute Demon King of Foreign Lands.
This is the story of a normal person who has eternal life, the story of how he watched countless events unfold and eventually becomes the Supreme Celestial of Eternal Life.