One cool Naruto fanfiction could be about a new character with a rare bloodline introduced during a filler arc. This character might have the power to control shadows in a unique way, different from Shikamaru's. The story could revolve around their journey to master this power and how they interact with the main Naruto characters during the filler events.
In the fanfiction, it might have Naruto using different jutsu or having different power levels compared to the canon battle. For example, he could have some new techniques that were not in the original story. Maybe his connection with the Nine - Tails is portrayed differently.
In general, the status of Naruto novels as canon can be a bit ambiguous. Some are closely tied to the main plot and characters, while others might be more like side stories or expansions that don't have a major impact on the core storyline.