Well, he might introduce his unique ninja skills to the Duel Academy. Maybe he'll use his shadow clone jutsu during duels, confusing his opponents. He could also make friends with some of the students there who are interested in his different fighting style.
Naruto going to Duel Academy in fanfiction would force him to grow in different ways. He would learn patience as dueling requires strategy and waiting for the right moment. His sense of competition would also be refined. Instead of just physical combat, he'd be involved in intellectual battles. This would add a new layer to his character, making him not just a strong fighter but also a smart strategist. He might also become more diplomatic as he has to interact with different types of students from the academy, some of whom may have different values than him.
Well, he might introduce some new spells from the wizarding world of Hogwarts. For example, the Patronus charm could be a game - changer in duels at Duel Academy. His knowledge of Defense Against the Dark Arts would give him an edge in battles.
Harry Potter's sense of strategy would improve. Duel Academy has its own set of rules and strategies for dueling. He'd have to learn and adapt to them, which would make him a more strategic wizard. He'd also become more open - minded as he experiences a different magical education system. He might start to question some of the things he learned at Hogwarts and find new ways of thinking about magic.
Well, he might find the whole boarding school thing really strange. Naruto is used to his village life in the Naruto world. At Yancy Academy, he'd probably be the odd one out with his ninja skills and energetic personality. He could get into trouble for using his ninja moves accidentally, like when he tries to jump from one building to another thinking it's normal like in Konoha.
Naruto's teaching style at Duel Academy would likely be energetic and motivational. He'd probably share his own experiences of growing up, facing challenges, and never giving up. His ninja training could also translate into teaching students discipline and perseverance in dueling.
The bijuu are the main characters as they are the focus of the 'goes to Yuki Academy' part. However, depending on how the story unfolds, there might be some side characters like the academy's janitor who has some secret knowledge about the bijuu and ends up helping them in unexpected ways, but still, the bijuu are the central figures.