Stellar Echo: Heart of the Myst - Chapter 84: VOL 2 : A display of influence, power, and ability.

Han Muye, who had exceptional comprehension skills, was reborn into a cultivation world. He joined a clan which specialized in swordsmanship. He then became the keeper who looked after the swords in the Swords Pavilion.

There were more than 100,000 swords stored in the pavilion. The keeper was tasked to clean all of them once a month.

When Han Muge cleaned the Qinghe sword, he acquired a hint of Sword Qi.

When he cleaned the Ziyan sword, he comprehended the swordsmanship, the Burning Plain, left behind by the original owner of the sword. He also acquired the Sword Qi of Burning Flame.

When he cleaned the Shanyue sword, he comprehended the teachings left behind by Master Boulder and learned the Mountain Sword Technique.

…

Han Muye built up his Sword Qi bit by bit during the past 60 years working as a keeper in the pavilion.

Throughout the 60 years, a disciple came to seek a sword in the pavilion, and he received guidance from Han Muye.

The Sacred Maiden from the demonic clan attempted to steal a sword from the pavilion, but in the end, she left dejected and empty-handed.

A swordsman came to challenge Han Muye, and he left with a broken sword.

…

60 years later, the Celestial World invaded the mortal world.

The disciple had become an exceptional Sword Deity. He wielded his sword and protected a part of the world.

The Sacred Maiden had become the demonic clan leader. She sent a letter to the Swords Pavilion and led her clan to fight against the gods.

The swordsman had achieved enlightenment in his swordsmanship. His Sword Qi rifled up to the sky.

…

The gods from the Celestial World loomed over the sky above.

Han Muye slowly stood up. 100,000 swords followed him as he emerged from the pavilion. His Sword Qi could be sensed from 30,000 miles away, and his Sword Will pierced through the realms.

He declared, “Today, I, Han Muye, will traverse the sky. I want to see who among the gods dares to invade this mortal world.”

For three years, Finn Taylor is utterly humiliated. He has endured everything from physical beatings to verbal abuse. For three long years, he has gone by only one identity—the useless matrilocal son-in-law of the Larson family. But this life as he knows it is about to be turned upside-down as he reclaims his position as the head of Peregrine Hall.

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

During the first known year, a magical mountain descended into the world from the realm of the Gods. Carved on this enormous mountain was a message: ‘Heaven Prevails’…

After the Grand Descent, a name that was given to the descending of the mountain, the Three Great Sages made their ways to Mystic Mountain where they learned to harvest what we now call magic, establishing the Mystic Cults and eighty-one sacred shrines to help aid mankind with the cult’s mystic powers against the eternal fight to the death with demons.

- Description from Novelupdates

This is the story of a person who transmigrated into a world with a radically different worldview.