Inexplicably Being Regarded as an Evil God?

Once I traveled to another world, I got a useless system. The function is to sell books for 999? Invincible from the start? Lottery? It doesn't exist at all. Fortunately, Yi Yan has a big heart. He can open a bookstore with peace of mind, get along well with his customers, make friends, and live a contented life. But... Are these guests illiterate? What he sells is clearly the Emperor's Internal Classics on How to Be a Good Butler, Sichuan Cuisine. How did it become some kind of soul-binding hell-flame bloodline cross? There must be something wrong with this world! PS: Di Huawen, the pace is not fast, the inspiration comes from the great god Shu Mooke, the title of the book I am really not the lackey of the evil god, the story, characters, and world background are all different, so I will not plagiarize. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.