I'm not entirely sure as I haven't read this specific fanfiction. But it might be a story that combines elements of the 'Naruto' universe with the idea of Naruto being the'son of Gondor' which could involve some sort of crossover between the Naruto world and the lore of Gondor from Middle - earth. Maybe it has Naruto possessing some of the traits or powers associated with Gondor.
Some popular ones could be 'Sword of the Rohan' which is known for its epic battles and complex characters. Another might be 'Rohan's Quest', a story full of mystery and adventure.
There could be multiple factors. His role models, whether they were his teachers, older siblings, or people he read about in books, might have inspired him. Also, the realization that hard work brings rewards, like good grades, praise from others, and a sense of accomplishment, would have made him keep up his hardworking attitude.
You could try searching on popular fanfiction websites like FanFiction.net or Archive of Our Own (AO3). Just type in 'naruto son of gondor' in their search bars and see if any relevant stories pop up.
He'd probably rule with a sense of fairness. Harry has always been one to fight for what's right at Hogwarts, so in Gondor, he'd ensure justice for all. He might set up new laws that protect the weak and punish the wrongdoers severely.
The Return of the Phoenix was a novel written by Inch Heart Orchid. The story was about a princess who was forced to marry the son of a slow-witted and sickly general. Although they had been married for three years, they did not have any real feelings for each other. However, when the country was in danger, the general's son used his life to protect the princess, making her realize the infatuation in his heart. However, they could not meet again in the end. The Di Princess regretted it, but it was already irreparable. The story also involved the conspiracy of the Shu brother and the rebirth of the Di princess. The entire story was full of twists and turns, emotions, and suspense.
Popular 'rohan x josuke fanfic' often focus on their unique dynamic. They might play up Rohan's eccentricity and Josuke's more straightforward nature. Also, a lot of them involve some sort of mystery or adventure that the two characters embark on together.
It could be about a conspiracy within the Rohan setting. Maybe it involves political intrigue among the Rohan characters, like a plot to overthrow the king or some secret alliance that goes against the common good in the Rohan realm.