A possible main villain could be Voldemort who somehow gains knowledge of Naruto's world and uses it to his advantage. He could learn to use chakra and combine it with his dark magic. He might create some sort of hybrid minions that are part - Death Eater and part - ninja. This would make him even more powerful and a greater threat to both the wizarding world and Naruto's world.
One possible interesting plot could be that Naruto is reborn in the Harry Potter world. He could bring his ninja skills and unique chakra system. Maybe he ends up at Hogwarts and becomes friends with Harry. He uses his shadow clone jutsu to help Harry in his adventures, like when they are facing Voldemort's minions. Naruto's determination and never - give - up attitude could also inspire the students at Hogwarts.
In some fanfictions, Harry might use his magic skills. For example, he could use spells to protect Naruto from a powerful enemy. Maybe he casts a shield charm to block an attack that Naruto couldn't avoid on his own.
I'm not entirely sure if there is a specific one with that exact premise. However, fanfiction authors are constantly coming up with new and unique concepts. Given the popularity of both Harry Potter and Naruto, it's possible that someone has written a story where Harry Potter is a blacksmith within the context of a Naruto fanfiction. It could be an interesting take on the characters and their worlds, perhaps exploring how Harry's skills as a blacksmith could interact with the ninja world of Naruto.
One great Naruto and Harry Potter crossover fanfiction could be where Naruto is somehow transported to the wizarding world and meets a Professor Potter. In this kind of story, Naruto might use his ninja skills in Hogwarts, like using his chakra to perform amazing feats that baffle the wizards. He could team up with Professor Potter to fight against dark forces that are threatening both the ninja world and the wizarding world.
The idea of the Master of Death in a Harry Potter - Naruto fanfiction might involve a crossover of abilities. For example, a character like Harry Potter who has mastered death could potentially teach the ninja in Naruto's world about different ways of facing mortality. It could also lead to some unique battles where the rules of both universes are combined. Like, using magic against chakra - based attacks while having the immunity to death that comes with being the Master of Death.
Well, in Naruto fanfiction, if there's a lightning wave, it could be related to the Uchiha clan's Sharingan abilities combined with lightning release. For example, a Uchiha character might be able to manipulate lightning into a wave - like form to attack multiple enemies at once. In Harry Potter fanfiction, the lightning wave could be a spell that was long forgotten but rediscovered by a young and adventurous wizard. It could be a spell that is difficult to control and has both positive and negative consequences, depending on how it's used in the story.
His chakra could be seen as a form of magical energy. He might be able to use it to enhance existing spells or create new ones. For instance, his Rasengan could be modified to have magical properties.
One idea could be that Naruto's immortality is due to some sort of ancient ninja magic that has parallels to the magic in the Harry Potter universe. For example, he could have made a pact with a powerful magical creature in the Naruto world that gives him eternal life, and when he enters the Harry Potter world, he has to figure out how this magic works there. Maybe he tries to find a way to share his immortality with his new friends in Hogwarts, like Harry, Hermione, and Ron. He could also use his ninja skills along with his immortality to protect the wizarding world from new threats that the regular wizards are not equipped to handle.
Yes. There might be some on fanfiction websites like Archive of Our Own. You can search for 'Naruto Harry Potter crossover Professor Potter' there. Some stories might have Naruto's skills being compared or combined with the magic in the Potterverse under the guidance of Professor Potter.