Yes, there are likely some fanfictions out there with this concept. You can try searching on popular fanfiction websites like FanFiction.net or Archive of Our Own. Just type in 'Naruto Brother of Zeref' in their search bars and see what comes up.
Yes, there might be such a fanfiction. It could be about Naruto somehow being connected to Zeref. Maybe Naruto gets transported to the world where Zeref exists and has to deal with Zeref's dark magic and his plans. It could also be a crossover where their powers combine in some unexpected ways, like Naruto's chakra interacting with Zeref's magic in a new form of combat.
Well, a plotline could be that Naruto is transported into Zeref's body. He has to figure out how to control Zeref's powers and deal with the people who are after Zeref. As he does this, he tries to introduce his own ideas of friendship and loyalty to those around Zeref. Maybe he even tries to find a way to end Zeref's curse of immortality using his ninja knowledge. It would be a complex story of adaptation and change.
Perhaps the plot could start with Naruto finding out he is Zeref's brother. This revelation could shatter his understanding of his identity. He then embarks on a journey to learn about his past and Zeref's motives. As he delves deeper, he discovers secrets about the two worlds (Naruto's and Fairy Tail's) that are intertwined. He has to deal with the conflict between his loyalty to his new - found family (Zeref) and his own moral compass. Maybe he tries to find a way to save Zeref from his own self - destruction while also protecting the people of both worlds from Zeref's potential threats.
There's 'Naruto and Zeref: The Bond of Brothers'. In this fanfiction, the author delves deep into their relationship. Naruto's positive attitude starts to influence Zeref, who has been rather dark - minded. They go on adventures together and learn from each other's strengths and weaknesses. It's a great read for those who like to see crossovers with character development.
The exploration of different worlds is also a common theme. Naruto is from the Hidden Leaf Village in his ninja world, and Zeref is from the Fairy Tail world. Fanfictions might have them travel between these worlds, comparing and contrasting the cultures, magic systems, and social structures. This not only adds an element of adventure but also helps in understanding how their characters would react in different environments. For instance, Naruto might be shocked by the prevalence of magic in Zeref's world, while Zeref could be intrigued by the ninja way of life.
Well, Naruto would probably be a very different character. Zeref has a dark and complex nature. Naruto might grow up with a different view on power and life. He could be more conflicted between his natural heroic tendencies and Zeref's influence which often leans towards the darker side of magic and existence.
Naruto's personality would be a blend of his original self and Zeref's traits. He may still have his determination but it could be a darker kind of determination. His sense of humor would probably be lost as Zeref doesn't seem the type to encourage light - heartedness. Also, he could be more secretive, not as open as he is in the original Naruto series because Zeref often keeps his own council.
One common theme is the power struggle. Zeref is extremely powerful, and Lucy has her own unique powers. Their relationship often involves how they deal with the power differential. For example, in some fanfictions, Lucy has to learn to hold her own against Zeref's overwhelming power.
A lot of these fanfictions also have a theme of redemption. Fem Zeref might be portrayed as a character seeking redemption for past actions, and Natsu could be the catalyst for that change. It's a way to give a new perspective to Zeref's character. Additionally, themes of friendship or unrequited love are also common. The relationship between Natsu and Fem Zeref can be explored in a platonic or romantic way, and often there are misunderstandings and moments of self - discovery related to these feelings.