The lightning wave could be a part of a prophecy in the crossover fanfiction. It could be foretold that a hero from the Naruto world and a hero from the Harry Potter world will combine their powers to create a lightning wave that will restore balance to both universes. Naruto could bring his physical combat skills and chakra control, while Harry could contribute his knowledge of magic and the power of love. The lightning wave then becomes a symbol of unity and strength, capable of defeating the ultimate evil in both worlds.
In a crossover fanfiction, the lightning wave could be a result of a magical experiment gone wrong. A Hogwarts student, perhaps Hermione, is researching ancient magic and accidentally creates a portal that sucks in Naruto. Together, they figure out that Naruto's lightning - style jutsu can be enhanced with Hermione's knowledge of magic, creating a new and more powerful lightning wave. This lightning wave could then be used to fight off dark forces from both the Naruto and Harry Potter universes, like the Death Eaters and the Akatsuki.
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.
A pet could have unique powers that are useful in both worlds. Let's say a pet has the power of invisibility in the Harry Potter world. In the RWBY world, this power could be used to sneak up on Grimm or avoid detection by enemies. The pet could also form bonds with characters from both universes. For example, it could befriend Ruby and also get along with Harry, and through these relationships, bring the two groups of characters closer together.
One way could be through a crossover spell. Maybe a powerful dark wizard in the Harry Potter universe discovers a way to create a Rinnegan - like power. They might use it to gain ultimate control over magic, similar to how the Rinnegan gives great power in Naruto. This could lead to a new kind of threat that Harry and his friends have to face.
One way could be through a magical portal. Imagine a portal opening between the Naruto universe and the Harry Potter world. Shisui, with his Sharingan abilities, could be a unique addition. His teleportation jutsu might be mistaken for a new form of Apparition in the wizarding world. Also, his skills in combat could be put to use in battles against dark wizards. For example, his ability to quickly assess and counter an opponent's moves would be very useful in duels at Hogwarts.
Well, in DxD fanfiction, the Naruto Black Lightning could be incorporated in various ways. For example, it could be a power that a character from the Naruto universe who somehow ends up in the DxD world brings with them. This power might be used to surprise the devils, angels, and fallen angels in the DxD world as it's a completely different type of energy compared to what they are used to. It could also potentially be combined with the magic or sacred gear abilities in DxD to create unique combat techniques.
One way could be through a magical spell gone wrong. Maybe a spell that was meant to transform an object into a helper, like in Beauty and the Beast, but instead it affects a character in the Harry Potter universe in a similar way. For example, a student might be turned into a beast - like form and only the love of another can break the spell, much like in the original Beauty and the Beast story.
The musical style of Hamilton can be incorporated by having the characters break into song - like numbers. For instance, Harry could sing about his quest to defeat Voldemort in a rap - like style similar to how Hamilton rapped about his life and goals. The lyrics could be filled with references to spells, magical creatures, and the battle between good and evil in the wizarding world.
In fanfiction, the gun could be a magical - Muggle hybrid weapon. It could have been created by a wizard who was fascinated by Muggle technology. Harry gets hold of it, and it has unique properties. For example, it could fire spells instead of bullets, or the bullets could be enchanted to have special effects. This would blend the two worlds of magic and Muggle - ness in an exciting new way.
One way could be through a powerful ancient magic spell. A wizard discovers an old, forgotten spell that can summon and bind a Nemean Lion as a familiar. This spell might be hidden in a lost grimoire in a dusty corner of the Hogwarts library.
The poisoned apple could be a gift sent by a mysterious figure to one of the characters, like Iron Man. When he touches it, it starts to release a dark magic that affects his suit's technology. Harry Potter then detects the magic and tries to find a way to reverse the poison's effects.