As a banished mercenary, Naruto would likely take on missions that require a lot of stealth and infiltration. Given his Uzumaki heritage and his own ninja training, he could be very good at getting into enemy strongholds. He may also take on missions to retrieve lost or stolen artifacts. These artifacts could be important to certain groups or villages, and Naruto would see it as his duty to return them. Additionally, he might be hired to mediate disputes between different groups, using his unique ability to understand different perspectives.
He might take on rescue missions. For example, rescuing hostages from bandits or rogue ninjas. Since he has a strong sense of justice, he'd be drawn to such tasks. He could also be hired for protection missions, like guarding a caravan traveling through dangerous lands.
Naruto could take on missions that the regular ninja villages wouldn't touch. Maybe investigating strange occurrences in remote areas. He might also get involved in smuggling - prevention missions, as his skills would be useful in stopping illegal trade. Another type of mission could be helping small, independent communities deal with local threats that they don't have the resources to handle on their own.
For the banished mercenary, his character development can be made interesting by exploring his backstory. If he was banished because of a misunderstanding, gradually revealing the truth behind it can be a great way to develop his character. He might initially be a lone wolf, but as he gets involved in various adventures, he realizes the importance of having comrades. His views on the shinobi way could change over time. For instance, he might start off believing that only power matters but then, after seeing the selfless acts of others, he begins to understand the value of things like loyalty and friendship. This transformation from a jaded mercenary to someone with a more positive outlook on the shinobi world would be very engaging.
Maybe Shion had a vision that was misinterpreted. People in the village might think Naruto was a danger based on that, so they banish him.
A possible plot could involve the banished mercenary being from a long - lost clan. The reason for his banishment was a false accusation by a rival clan. As he wanders the Naruto world as a mercenary, he discovers clues about his clan's true heritage and power. He then uses his skills as a mercenary to gather allies and resources to prove his clan's innocence and restore its honor. Along the way, he crosses paths with Naruto and his friends and they either help or hinder his quest depending on the situation.
One idea could be that the banished mercenary has unique jutsu skills learned from different lands during his mercenary days. He could return to the Naruto world with a new perspective and hidden motives, perhaps trying to unite different ninja clans against a new, greater threat. Another plot idea is that he has a connection to an ancient prophecy that was thought to be forgotten, and his banishment was actually part of a grand scheme to protect him until the time was right.
It could be an original character. For example, a ninja who was born into a minor clan but had great potential. However, due to political intrigue and jealousy from a major clan, he was framed and banished. He then became a mercenary to survive. Another option could be a character who was once a part of a secret ninja organization and was banished when he disagreed with their methods. Now, as a mercenary, he returns to the Naruto world with a vendetta against those who wronged him.
They could undertake missions to stop dark magic users. With Zeref's knowledge of dark magic and Naruto's combat skills, they would be well - equipped. For example, if there was a mage using forbidden spells to cause chaos, their guild could be called in to stop it.
Missions involving diplomatic relations could also be on the table. Naruto has a way of making friends and influencing people, and Itachi's calm and composed presence could add an air of authority. They could be sent to mediate between feuding ninja villages. Another type of mission could be rescuing important hostages. Naruto's determination and Itachi's stealth and combat abilities would make them a great team for this. Itachi could silently take out the guards while Naruto locates and frees the hostages.
Well, his life changes in many ways. Firstly, he has to find his own clients as a mercenary, which is very different from his village - assigned missions. He probably has to travel to different regions and learn about new cultures. Also, without the village's resources, he has to take care of his own equipment and training. He may form alliances with other outcasts or mercenaries. And he might develop a more cynical view of the ninja world, since he was banished from the place he once called home.
If Naruto was banished in fanfiction, it would likely be a turning point. He could encounter new allies and enemies, and his character could undergo significant changes as he adapts to his new situation. Maybe he'd even discover hidden powers within himself.
In this kind of fanfiction, Naruto might face a lot of challenges. He could be isolated from his friends and the village he loves. Maybe he has to deal with local problems at the outpost all by himself, like fending off wild beasts or bandits. Also, he might start to question his place in the world since he was banished.