Maybe Jinx is on a mission in her own world to steal some powerful tech. But she accidentally activates a portal and ends up in Naruto's world. The shinobi there think she's a new kind of threat. Naruto, though, is intrigued by her unique weapons and unorthodox fighting style. He tries to convince her to use her skills for good in the Naruto universe, and they end up teaming up against a common enemy that is threatening both their worlds.
One idea could be that Jinx somehow gets transported to the Naruto universe. She might initially be seen as a strange and powerful figure. Naruto, being the curious and friendly type, would approach her. Jinx could then start causing chaos in the Hidden Leaf Village, which Naruto has to deal with while also trying to understand her. And they could gradually form an unlikely friendship as they learn from each other's worlds.
A different approach could be a time - travel fanfiction. Jinx accidentally travels to Raven's past and disrupts things. Raven has to figure out how to send Jinx back while also dealing with the changes Jinx has caused in her past. This could lead to some really interesting interactions as Raven tries to understand Jinx's chaotic nature in a different time period.
A more in - depth fanfiction could be about Jinx being a long - lost relative of a ninja clan in the Naruto world. Maybe she has some latent ninja abilities that she doesn't know about. Naruto helps her discover these powers and she has to choose between her old life of mayhem and a new life as a ninja, with Naruto guiding her through the process.
A different approach could be that characters from the Matrix world are brought into the Naruto universe. Trinity could learn some ninja techniques from the Konoha ninja. The Matrix characters would be amazed at the concept of chakra and how it can be used for various powers, like walking on walls or creating fireballs.
Well, it could work by having a magical or technological portal that connects their two worlds. Jinx could be curious and step through it into the Naruto world. Then, the story could revolve around the culture shock for Jinx and how the Naruto characters react to her strange appearance and explosive devices.
Perhaps the One Ring could have an unexpected reaction to Naruto's chakra. It could either be attracted to it or repelled. This could create an interesting plot where Naruto has to deal with the power of the Ring while also trying to find a way back to his own world.
One idea could be a Naruto crossover with One Piece. Naruto and his friends could end up on the Grand Line and have to navigate the dangerous seas while also dealing with pirates. They might team up with the Straw Hat Pirates to fight a common enemy, like a new Akatsuki - One Piece hybrid organization.
Some fanfictions might focus on the idea of a character from Naruto being a part of the Kingsman recruitment process. Imagine Sasuke being scouted by the Kingsman for his natural combat abilities and sharp intellect. He would have to go through their rigorous training, which could be a really interesting take as we see how his ninja skills would fare in a different kind of combat and discipline environment. There could also be a plot where the Kingsman need the help of Naruto's Nine - Tails chakra for a special mission that requires an extraordinary amount of power.
One idea could be that Danny and Jinx accidentally cross paths in a dimension where the laws of magic and the supernatural are all jumbled. Danny is trying to find his way back home and Jinx, initially seeing him as a threat, later realizes they can help each other. They team up to navigate through this strange dimension and along the way, they learn about each other's powers and develop an unlikely friendship.
Another concept is that a common enemy forces Naruto and Hellboy to team up. This enemy could be a powerful being that has the ability to disrupt both the ninja world and Hellboy's world. Naruto's jutsu and Hellboy's brute strength and Right Hand of Doom could be combined in creative ways to fight this foe.
Another possibility is that a villain in the Naruto world tries to use Nunnaly for her unique knowledge or skills. The shinobi of the Hidden Leaf, including Naruto, would then have to protect her. In the process, Nunnaly could learn about the values of the shinobi world like loyalty and perseverance.