A great Minato and Kushina fanfic often has a deep understanding of their characters. For example, showing Minato's intelligence and leadership skills along with his love for Kushina. And for Kushina, highlighting her strong will and the love she has for Minato and the village. If a fanfic can capture these aspects well, it's on the right track.
He uses his skills as a ninja to protect Naruto. He sets up special seals around Naruto's crib to keep out any potential threats. Also, Minato might try to use his chakra to boost Naruto's weak body. He would transfer his own life force a little bit at a time to help Naruto fight the sickness, which is a huge sign of his love.
Minato might show his protectiveness by always being near Naruto in spirit. For example, he could leave behind some kind of jutsu or power that activates when Naruto is in great danger, like a hidden seal that releases a powerful defense.
In the fanfiction, Naruto could show his genius in leadership, just like Minato. Minato was respected as a leader. Naruto may inspire others around him with his determination and positive attitude. He could come up with innovative plans to protect the village and its people, much like Minato did. Also, Naruto's ability to understand people's feelings and bring them together could be a sign of his genius in this aspect.
The plot is also very important. It could be a story that explores their relationship in a new and interesting way. Maybe it's set in an alternate universe where they meet under different circumstances. Or perhaps it delves deeper into the lore of the Persona world in relation to their connection. Good fanfics also have engaging dialogue that makes the characters come alive.
Well, Naruto fans are always interested in the untold stories. Kushina and Minato are key figures in Naruto's life, yet we don't get to see a whole lot of their time together in the original anime/manga. Fanfictions fill this gap. They can create different storylines around their powers, their relationship with the village, and most importantly, their relationship with each other and Naruto. The possibilities are endless, which is why it's so popular.
The idea of Minato being Naruto's brother is appealing because Minato was such a powerful and respected ninja. It gives Naruto a different kind of support system from the start. In a fanfiction, it can explore how Naruto could have developed with Minato by his side, which is very different from his original lonely childhood.
Minato's unique abilities make him a great addition. His teleportation skills, for example, can add a new dimension to the battles and adventures in the Fairy Tail world. It's something that the regular Fairy Tail mages don't have, so it brings a fresh element.
Naruto's character development includes learning about sacrifice and the importance of bonds. In the fanfic, his refusal of Minato could be a sign that he has outgrown the need for a father figure in the traditional sense. He has formed deep bonds with others like Iruka, Kakashi, and his friends. These relationships have made him strong enough to face Minato and say no if he feels it's necessary for his own growth and the protection of those he cares about.
The appeal lies in the contrast. Minato is a highly respected and powerful ninja. Female Naruto, on the other hand, can be written with her own set of strengths and a different personality from the male Naruto. Their relationship can be explored in unique ways, like how Minato might mentor her in a different way compared to the other ninjas.