Traveling through time and becoming a sect's eldest disciple, only to be exiled to the Demon Tower at the beginning?

In the thousand-year-old lonely demon tower, Lin Changqing raised his hand and touched the dusty stone tablet.

[The host carefully observes the inscription, activates his heaven-defying comprehension, and suddenly realizes the technique: Qingyun Sword Technique]!

Under the system of heaven-defying comprehension, Lin Changqing began to have sudden enlightenment every day!

[The host sweeps the floor, sighing at the falling leaves, and suddenly realizes the skill: Lion's Sky Seal.]

[The host seems to have gained something from drinking tea, and suddenly realizes the technique: Dragon Elephant Infinite Skill.]

……

Eighty years have passed since the Demon Tower, and the world is on the verge of collapse. Thousands of monsters have invaded, and the demons have come to the sect to kill.

Lin Changqing, with black hair and white hair, walked out of the demon tower with a sword in hand.

[The host walked out of the demon tower, suddenly realized the critical strike, and became a land sword immortal! ]

[Ding! Signed in at the True Martial Grand Hall, obtained 200 years of Zhang Sanfeng's cultivation!]

[Ding! Signed in at Qingwei Palace, obtained Pure Yang Wuji Arts!]

[Ding! Signed in at Ziwei Grand Hall, obtained Pei Yuan Pills!]

Lin Chuan, residing on Wudang Mountain, has been signing in for fifty years. His divine arts are perfected, and he's nearing the Grand Dao. Yet, he can only spend his days herding cattle and enjoying the scenery, forbidden from descending the mountain.

Finally, one day, the Six Great Demonic Cults surrounded Wudang Mountain, and they chanced upon a cowherd boy...

[Ding! Signed in at the True Martial Grand Hall, obtained 200 years of Zhang Sanfeng's cultivation!]

[Ding! Signed in at Qingwei Palace, obtained Pure Yang Wuji Arts!]

[Ding! Signed in at Ziwei Grand Hall, obtained Pei Yuan Pills!]

Lin Chuan, residing on Wudang Mountain, has been signing in for fifty years. His divine arts are perfected, and he's nearing the Grand Dao. Yet, he can only spend his days herding cattle and enjoying the scenery, forbidden from descending the mountain.

Finally, one day, the Six Great Demonic Cults surrounded Wudang Mountain, and they chanced upon a cowherd boy...