Reverend Insanity
Gu Zhen Ren's xianxia serialized webnovel Reverend Insanity, also known as Gu Daoist Master, was initially published by Qidian but was later prohibited by the Chinese government just before the author was able to publish the final few chapters.
The narrative starts hundreds of years ago when Fang Yuan, an Earthly Chinese official, is strangely reborn into a magical realm where Gus are magical insects who, according to Chinese legend, bestow magical abilities on their masters, known as Gu Masters. He survives for several centuries, going through various traumas that strip him of his prior moral code.
The story culminates with him creating or "refining" a Gu that allows the user to travel back in time via the River of Time. This leads to various groups of people coming together to assassinate him, at which point he first activates the time-turning Gu, the Spring-Autumn Cicada.
He has successfully traveled back in time to his early adolescence, bringing with him all the wisdom and convictions of an adult. Despite all obstacles, he is steadfast in his pursuit of his amoral worldview and eternal existence. There is a current English translation of the work, which is almost 2,300 chapters long in Chinese and accessible on Qidian's English language platform.
Author: Gu Zhen Ren
Released: 2018 - Ongoing
Chapters: 11
Read here: https://www.manhwaden.com/manga/reverend-insanity/