Well, in a fanfiction like this, maybe Naruto is given the devil fruit as a gift from a mysterious being. However, he quickly realizes that it's affecting his chakra system in a negative way. So, he abandons it. Later, an enemy gets hold of the fruit and becomes extremely powerful. Naruto then has to use his ninja skills and the power of friendship to defeat this new foe.
The ninja world could change a great deal. If Naruto abandons a devil fruit, and it falls into the wrong hands, like say Orochimaru's, he could use it to create even more powerful and terrifying jutsu. This would force the other ninja villages to band together against this new threat. Also, the concept of power in the Naruto world would be redefined as devil fruit powers are so different from chakra - based abilities.
Well, it could have been about a character from Naruto ending up in the Devil May Cry universe. Maybe Naruto himself gets transported there and has to use his ninja skills to fight demons. He might learn new abilities from the Devil May Cry characters, like Dante's swordsmanship or Vergil's cool moves. And perhaps there would be some sort of conflict between the ninja way and the demon - hunting way of the Devil May Cry world.
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.
Well, if Naruto had a Logia Devil Fruit, it would completely change his power set. He could become intangible like most Logia users. For example, he could turn into an element and avoid attacks easily. His combat style would be more about strategic use of his new intangible form rather than just relying on his ninja skills.
Well, Naruto eating a Logia devil fruit would be really interesting. He is known for his ninja skills in the Naruto universe. But with a devil fruit, things would change. Logia fruits are special in the One Piece world. If Naruto had one, say a Logia fruit that gives the power of lightning. He could use his new lightning powers to enhance his speed even more. His movements could be as fast as lightning strikes, and he could also use the lightning to attack his enemies from a distance. This would be a whole new way of fighting for him, different from relying solely on his ninjutsu and taijutsu.
In the fanfiction, if Naruto finds a devil fruit, it could lead to some interesting alliances. Maybe he would team up with some characters who are interested in this new and strange power source. For example, Sasuke might be both intrigued and a bit jealous, which could create a whole new dynamic between them. Also, the Akatsuki might try to steal the power from Naruto, leading to a series of intense battles.
Well, if Naruto had the Phoenix Devil Fruit in a fanfiction, his fighting style might change completely. He could use the fire - based powers of the phoenix to enhance his existing jutsu. For example, his Rasengan could be infused with phoenix fire, making it more powerful and having the added effect of burning his opponents. Also, the regeneration aspect would allow him to take more risks in combat.
One possible ability could be the power to manipulate time. Just like Doflamingo's string powers in One Piece, but applied to time. A character in Naruto fanfiction with this Devil Fruit ability could slow down or speed up time during battles. This would give them a huge advantage, as they could dodge attacks easily or land multiple strikes while the enemy is frozen in time.
In Naruto fanfiction, a godlike Devil Fruit would be a game - changer. Imagine a Devil Fruit that gives the user the power to read minds. This would be extremely useful in espionage and combat. In the Naruto world, where information is crucial, this power could turn the tides of war. However, it might also have negative consequences. The character with this power could become corrupted by the knowledge they gain, or other characters might fear and isolate them due to the invasion of privacy.