If you want to have more subclasses in your novel, then I recommend two novels: "God-level Full-time System" and "All-class Martial God". The former included seven manufacturing sub-professions, including jewelry, alchemy, forging, tailor, engineering, enchantment, and leather making. There were also six production sub-professions, including mining, cooking, herbal medicine, skinning, fishing, and first aid. In the latter, mages, archers, equipment masters, enchanters, alchemists, and other awesome occupations became the secondary occupations of a warrior. They could make your protagonist a versatile character in the novel. Not only could he fight, but he also knew how to create various props to assist in battle. Of course, the above was just a suggestion. In the end, it still depended on the type of novel and plot you wanted to choose. I hope you like this fairy's recommendation. Muah ~😗