In such a fanfiction, perhaps the butterfly could be a symbol of a new beginning in the Naruto world. It might signify a change in the destiny of a character. For example, Naruto himself could encounter this special butterfly and it could bring him a new power or a different perspective on his journey to become Hokage.
It could be Naruto. Since he is the main character in the original series, it would be natural for him to be the focus in this fanfiction as well. The butterfly could have a special connection to him, like guiding him on a new adventure or helping him unlock a new level of his power.
Heroic Mist Spreading Its Wings Memories of When He Was Young with His Sister was an episode in the fourth season of Heroic Mist. In this episode, the main character, Qian Xun, and her sister Qian Yan-daren recalled the times when they played together when they were young and showed their deep feelings for each other. This episode was very touching and left a deep impression on the audience.
His wings could give him an advantage in combat. He could use them for quick aerial maneuvers, like swooping down on enemies from above and catching them off guard. Also, he might be able to use his wings to block attacks, like a shield of feathers. However, they could also be a liability if an enemy manages to grab or damage them.
Most official platforms would not allow such inappropriate fanfiction. Fanfiction should be about creativity within the boundaries of respect for the source material and its characters. Instead of seeking such a fanfiction, you could search for ones that depict their relationship in a more platonic or mentor - mentee style, which are much more common and in line with the spirit of the 'Harry Potter' universe.
Serana is also a popular love interest. As a vampire, she has a complex personality and her own set of powers. The relationship between her and the Dovahkiin can be filled with both passion and danger. Also, there's Ysolda. She is a young woman in Whiterun with dreams and a kind heart. Her more normal life compared to the Dovahkiin's adventures can create an interesting contrast in a romantic relationship.
The dovahkiin's dragon shouts would be a huge advantage. For instance, his 'Unrelenting Force' shout could clear paths through enemy lines. This would make it easier for the fellowship to move forward in dangerous terrains filled with enemies.
Well, having wings could make Percy more independent. He can now reach places on his own without relying on his friends as much. This might cause some tension in his relationships at first, but it also forces him to grow and learn how to balance his new independence with his need for his friends. For example, he might fly off to scout ahead during a quest and have to make quick decisions on his own, which is a big step in his character development.
A common theme is empowerment. Female Dovahkiin are often shown rising above the limitations set by the society in the game world. For example, in many fanfictions, they break through the gender barriers in combat and leadership roles.
Sure, there are 'Harry Potter Dovahkiin' fanfictions out there. You might come across ones where Harry has the powers and characteristics of the Dovahkiin. This could lead to really interesting plotlines, like him using dragon shouts in the wizarding world or having a different approach to dealing with the dark forces. It can be a really cool crossover concept for fans of both universes.