Perhaps it's a minor character from the original Naruto series who didn't get much spotlight before. For example, a ninja from the Hidden Leaf who has always admired Kakashi and now gets the chance to be his apprentice. This character could have some hidden abilities or a strong motivation to become a great ninja under Kakashi's guidance.
It could also be a character from another ninja village who somehow ends up in the Hidden Leaf and becomes Kakashi's apprentice. This would add an interesting dynamic as they bring different ninja traditions and values, and Kakashi has to adapt his teaching methods to suit this new apprentice.
It could be an original character created specifically for the fanfic. Maybe a young ninja with a unique kekkei genkai that Kakashi sees potential in.
Well, in this fanfic, perhaps there's a plotline where the apprentice discovers a long - lost ninja art and Kakashi helps them develop it. This could lead to the apprentice becoming a key figure in the village's defense against a new threat. Or it could be about the apprentice facing personal challenges, like dealing with self - doubt, while Kakashi tries to instill confidence in them through various training methods.
One of the key elements is the exploration of Naruto's new powers. Since he's becoming godlike, the fanfic might show how he struggles to control these immense powers. Another element is the role of Kakashi. As his teacher, Kakashi has to guide Naruto, and this relationship can bring out many emotional and growth - related storylines. Plus, the fanfic may also include how Naruto's new status affects the ninja world around him, like how other villages react to his power.
It might be one of the existing minor characters from the Naruto series who finally gets a chance to shine as Kakashi's apprentice. For example, that one ninja from the background who always admired Kakashi from afar and now has the opportunity to be his student.
The apprentice could be a new genin who shows great potential in the field of intelligence gathering. Maybe someone with a sharp mind and an ability to stay calm under pressure, like Shikamaru. He has the intelligence and strategic thinking that would make him a good candidate for Ibiki's apprentice.
It could be a rogue ninja from a rival village who is after the apprentice's special abilities. This rogue ninja might see the apprentice as a threat or a tool to achieve their own evil goals.
A young ninja with a lot of potential but also some major flaws could be a great main character. For example, a ninja who is very powerful but lacks self - control. The sennin could then focus on teaching them not just ninja skills but also self - discipline.
It could be an original character created just for the fanfic. Maybe a young wizard or witch who has a special talent for alchemy and catches Flamel's eye.
It could be Orochimaru. Since Anko has a history with Orochimaru, and Nariko being Anko's apprentice, Orochimaru might see Nariko as a threat or a tool to get to Anko. He could try to manipulate Nariko into doing his bidding or try to steal her newfound skills.
One common theme is growth. The apprentice usually starts off inexperienced and through Sakura's teaching, grows in power and knowledge.
One popular 'sakura kakashis apprentice fanfiction' is 'The Apprentice's Journey' which delves into the relationship between Sakura and her apprentice. It has an engaging plot that shows the growth of the apprentice under Sakura's guidance.