It could be Gaara. Although he is now a kage, in a fanfiction scenario, he could put aside his current role for a special mission for Naruto. His ability to control sand, which can be used both offensively and defensively, would make him a formidable assassin. He can move silently through the desert and use his sand to ambush enemies. Additionally, Karin could be a potential assassin. Her sensing abilities are top - notch, and she has some combat skills too. Naruto might hire her to track down and eliminate a target with her unique skills.
Sasuke could be a likely candidate in a sense. Given his skills as a ninja, his Sharingan which gives him an edge in combat and perception, and his past as a sort of 'rogue' ninja. He could be in a situation where Naruto has to hire him for a special mission that requires his unique abilities. Another possibility is Kakashi. He has a vast array of skills, is very intelligent, and could easily take on the role of an assassin if needed, even if it goes against his normal moral code slightly. He would do it for Naruto's sake.
Well, a plot could be that Naruto hires an assassin to eliminate a group of rogue ninjas who are targeting his friends. The assassin might be a former enemy who has a change of heart. They then embark on a journey together, with the assassin teaching Naruto some unorthodox combat techniques. Also, the story could be about Naruto hiring an assassin to stop a dark ritual that is about to be performed in the shinobi world. The assassin has special abilities that are crucial to the success of the mission.
Jiraiya could be an interesting assassin master. He already has a lot of knowledge and skills that he could pass on to Naruto in a more assassin - like way. His experience in espionage and combat would make him a great fit.
An OC (original character) could be a godlike assassin. This gives the author complete freedom to create a character with the perfect set of skills, a mysterious background, and a unique personality. They could have powers like teleportation or the ability to control time briefly, which would make them extremely powerful and godlike in the Naruto universe.
Well, there are quite a few. You can check out fanfiction websites like FanFiction.net or Archive of Our Own. Some might focus on a hired assassin in the Naruto universe with unique plot twists, like an assassin who has a change of heart due to Naruto's influence.
It could be a former Auror who has turned to more shadowy ways of dealing with threats. After seeing the inefficiency of the Ministry's methods in some cases, they decide to take matters into their own hands and become a sort of assassin to target dark wizards.
A highly trained assassin with both ninja and pirate skills could also be the most powerful. Imagine an assassin who has mastered the art of silent killing like a ninja but also has the knowledge of poisons and navigation like a pirate. This character could move in the shadows, taking out opponents without being detected, and using their diverse skills to outwit any enemy, be it a powerful ninja like Naruto or a fearsome pirate captain.
Sure. Given the popularity of the 'Percy Jackson' books, there are all kinds of fan - created stories out there. Some fans like to twist the original character traits and storylines. Making Percy a hired assassin is a way to put a new spin on the character. It could involve him using his demigod powers in a more morally ambiguous way compared to the original stories.
Haku is another character that is quite popular. Given his background as a ninja with assassin - like abilities in the original series, fanfiction writers can expand on his story. He could be part of a secret assassin organization or be a target of other assassins.
The main difference is the central character of the hired assassin. In other Naruto fanfics, the focus could be on the regular Naruto characters like Naruto himself, Sasuke, or Sakura. But in 'hired assassin Naruto fanfic', the assassin's perspective and their unique skills and motives drive the story.
It could be an original character. For instance, a ninja who was wrongly framed for a crime and banished. They would then be the focus as they navigate their new life as an assassin.