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.
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.
Another option could be Luna Lovegood. She has a very unique perspective on magic already. If she were Merlin's apprentice, she could bring her eccentric ideas and combine them with Merlin's ancient magic. Her friendship with Harry Potter and the others could also play a big role in how she uses her newfound status as Merlin's apprentice to help the wizarding world.
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.
Maybe an orphan from a non - Uchiha clan who has a special ability that Madara finds interesting. This character would be malleable and eager to learn from Madara, as they have no other real family or guidance. They could bring a fresh perspective to Madara's teachings.
It could also be a character from outside of Hogwarts. Maybe a young wizard who has been self - taught in some dark magic and Dumbledore takes them as an apprentice to guide them towards the light side of magic. Dumbledore would see the potential for good in this character and want to reform them.