One possible plot twist could be that the gun magic is actually a curse in disguise. Maybe it seems powerful at first, but it slowly starts to corrupt Fem Naruto, and she has to fight against its dark influence.
One plot twist could be that the gun is actually a magical object in disguise. It might have been created by a dark wizard who wanted to introduce an element of Muggle - like violence into the wizarding world. Harry discovers this as he tries to use it and realizes that it has powers beyond what he expected. Another twist could be that the use of the gun makes Harry an instant target for both the wizarding authorities and dark forces. He has to constantly evade capture while trying to figure out why the gun has such a strange allure and power.
One possible plot twist could be that her family has a secret reason for neglecting her. Maybe they're trying to protect her from some greater danger. Another could be that she discovers she has a hidden power that makes her family regret their neglect.
Well, there might be a fanfiction where the Akatsuki are the ones who first introduce guns to the shinobi world. They use it as a way to gain an upper hand in their quest for the tailed beasts. Naruto then has to figure out not only how to counter these new weapons but also understand why the Akatsuki are using them and what their endgame really is. This would completely change the power dynamics in the Naruto story.
It could be that Fem Sasuke is under some sort of mind - control when she kidnaps Naruto. A powerful enemy, like Orochimaru or a new villain, might have used a jutsu to make her do this. As the story progresses, Naruto would then have to find a way to break the mind - control on Fem Sasuke while also dealing with the situation of being kidnapped.
There could be some really creative interpretations in such a fanfiction. Maybe in this version of the story, Fem Naruto uses gun - like magic as a way to fight in a more modern - style combat while still having the essence of the Naruto universe. For example, her 'gun magic' could be powered by chakra and have unique abilities like shooting out elemental bullets. However, finding such a specific fanfic can be a challenge, and it might require some patience while browsing through the fanfic archives.
Another plot twist might be that the technology in Bond's world starts to affect Naruto's chakra. For instance, he's exposed to a new type of radiation that either enhances or weakens his powers in unexpected ways. This would force both of them to find a way to deal with this new situation and also change the dynamic of their partnership.
He could use elemental magic like fire, water, air, and earth magic. Since he already has an affinity for certain elements in the original Naruto series, it would be easy to translate that into magic forms. For example, his Rasengan could be transformed into a magic - infused attack.
A plot twist could be that fem Tsukune is actually a long - lost relative of a powerful Naruto character. Maybe she has some special bloodline that links her to someone in the Naruto universe, and this discovery changes the whole dynamic of the story.
A possible plot twist could be that Naruto discovers he has a hidden connection to Smaug. Maybe he is related to Smaug in some long - lost magical way. Another twist could be that Smaug is not really a villain in this fanfiction. Instead, he is being controlled by a greater evil, and Naruto has to figure out how to free Smaug from this control. It would change the whole dynamic of their relationship from one of enmity to a more complex situation where they could potentially become allies.
A possible plot twist could be that Naruto turns out to be a keyblade wielder in disguise. This would completely change the dynamic as everyone in the Naruto world and Kairi would be shocked. It could also mean that Naruto has a whole different origin and mission related to the world of Kingdom Hearts.