The 'scaramouche novel' could cover a wide range of topics. It might be set in a historical period, a fantasy world, or a science - fiction realm. If it's a historical novel, perhaps Scaramouche is a real - life figure or based on one. In a fantasy setting, he could be a wizard, a knight, or some other extraordinary being, and the novel would follow his journey through that magical world, dealing with magical creatures, political intrigue, and personal quests.
I don't know the author of the 'scaramouche novel' without more information. There are many novels with this name or a similar name, and different works may have different authors.
Inosuke doesn't become a Hashira in the manga. The story progresses with him having other significant experiences and achievements instead of achieving that specific position.