In most One Piece lore, those who eat Devil Fruits lose the ability to swim. However, in this fanfiction, perhaps the author has created a unique workaround. Maybe Naruto has some special jutsu or power-up that allows him to overcome the typical Devil Fruit drawback and swim. Another possibility is that the Devil Fruit he has is an entirely new type, not bound by the normal rules, which gives him the ability to swim.
One implication could be that it completely changes the power dynamics in the story. Usually, Devil Fruit users are at a huge disadvantage in water, but if Naruto can swim, he has an edge over other Devil Fruit users. This could make him a more formidable opponent. Also, it might change how other characters in the fanfiction view him. They might see him as an anomaly or something to be feared because he doesn't have the typical weakness.
If Naruto ate a Paramecia Devil Fruit, his physical abilities might change drastically. For example, if it was a rubber - like Paramecia fruit, his already acrobatic fighting style could become even more so. He could stretch his limbs to attack from unexpected angles, much like Luffy in One Piece. This would give him an edge in close - combat situations, and his opponents would have a hard time predicting his moves.
If Naruto had the Fire Devil Fruit, his combat style would change drastically. He could combine his existing ninja skills with the power of the fruit. For example, he might be able to infuse his Rasengan with fire, making it even more powerful. Also, his mobility could be enhanced as he could use fire to propel himself in new ways. This would make him a more formidable opponent in battles against strong foes like Sasuke or Pain.
In Naruto fanfiction where Devil Fruits are involved in the Chunin Exams, it could lead to some really interesting scenarios. For example, a character might eat a Devil Fruit and gain unique powers that completely change the dynamics of the exams. They could use abilities like Luffy's stretchiness from the Gomu Gomu no Mi to reach far - off targets or avoid attacks in a creative way.
In a Konoha fanfiction where Naruto has a Logia Devil Fruit, he could have amazing new powers. For example, if it was a fire - based Logia fruit, his Fire Style jutsu could be enhanced to a whole new level. He might be able to transform his body into fire completely, making it difficult for enemies to land a hit on him. Also, this new power could change the power dynamics in Konoha, as he would be even more formidable against threats both inside and outside the village.
One possible scenario in this fanfiction could be Naruto obtaining the ice devil fruit. This would completely change his combat style. He could use ice attacks in combination with his existing ninja techniques. For example, he might freeze an opponent's feet with ice and then follow up with a Rasengan. It would also add a new element to his character development as he'd have to learn to control this new power.
The Fire Devil Fruit could make Naruto more confident. Having such a powerful ability would give him an edge in battles and make him feel more capable. This newfound confidence could also change how he interacts with his friends and allies. He might be more assertive in leading them.
One idea could be that Naruto somehow obtains a Dragon Devil Fruit. He then gains the abilities like flying, breathing fire or some other dragon - like powers. This would completely change the dynamics of his battles in the Naruto universe. He could use his newfound flight to gain a strategic advantage over his opponents and his fire - breathing could be a powerful offensive move.
The reaction would be mixed. The Hidden Leaf Village might initially be excited as Naruto is always finding new ways to protect them. But as they realize the implications of a Devil Fruit power, there could be concerns. Other villages would likely be intimidated. They might start to form alliances against the Leaf out of fear that Naruto's new power could be used to dominate them. However, some shinobi might also be inspired by Naruto's new ability and try to find ways to counter it, which could lead to a new era of power - seeking and innovation in the ninja world.