I Am Spelling the Heavenly Book in the Nine Realms

It is said that there is an extremely mysterious realm hidden among the nine realms, called the Cloud Realm. A fledgling young gunslinger accidentally discovers a prophecy of world-ending catastrophe. With the emergence of a mysterious heavenly book, can the young heroes find the answer to saving the world? (The introduction is so difficult to write. The author is slow to update due to late procrastination, but I hope I can finish the story.)