Yes, there are likely fanfictions out there with such a concept. Fanfiction platforms are full of creative and often wild ideas. You can check major fanfiction websites like FanFiction.net or Archive of Our Own (AO3). Just search for the relevant tags or keywords to find them.
Natsu could inherit the ability to use chakra. This would give him an extra edge in combat, allowing him to perform jutsus like Naruto. Maybe he could even learn the Rasengan, which he could combine with his fire magic for a super - powerful attack.
It could be a wild mix of the Naruto and Fairy Tail universes. Maybe Naruto's ninja skills would be passed on to Natsu in some unique way. There could be epic battles with Natsu using Naruto - style jutsu.
In some fanfictions, Acnologia is made out to be Natsu's father. But this is not part of the original canon of the Fairy Tail series. Fanfiction writers often like to create such unexpected family relationships to add new twists to the story.
Well, in such a fanfiction, their relationship might start off with Natsu being in awe of Naruto's powerful abilities. Naruto, being a father, would likely try to teach Natsu about his own ninja skills. They could bond over training sessions, with Naruto passing on his wisdom about perseverance and friendship. Natsu would probably be eager to learn and might even combine his own magic with Naruto's ninja techniques in creative ways.
Yes, there are likely some fanfictions out there with this concept. The 'Naruto' and 'Fairy Tail' (where Natsu is from) fandoms are both quite large, and fans often like to create crossovers that connect different universes in interesting ways.
In a fanfiction about the return of Natsu's foster father dragon, perhaps the dragon returns with a mission. He might have learned of a great threat during his time away and has come back to enlist Natsu's help. This could involve traveling to new and dangerous lands, encountering unique magical creatures, and Natsu having to prove himself once again to his foster father. The story could explore their relationship, which may have some strain due to the long separation.
Maybe they embark on a journey to save their respective worlds from a common threat. A powerful demon or an evil wizard is trying to destroy both the Naruto universe and the Fairy Tail world. Naruto and Natsu would travel across different dimensions, gathering allies from both worlds. Naruto would use his Rasengan and Natsu his Fire Dragon's Roar to fight off hordes of minions while they search for a way to stop the main villain.
Yes, in certain fanfictions. Fanfic writers like to play around with established concepts. They might see Kurama's close bond with Naruto and decide to create a scenario where Kurama is Naruto's father. This can lead to really interesting and unique story developments that deviate from the normal Naruto narrative.