Well, he'd probably become super powerful. The symbiote suit could enhance his physical abilities like speed, strength, and agility. He might also gain some new jutsu or combat techniques based on the nature of the symbiote. For example, if the symbiote has some sort of dark or shadow - like property, Naruto could incorporate that into his attacks, making them more unpredictable.
If Naruto gains a symbiote suit in fanfiction, his character development would be multi - faceted. He would initially be excited about the new power, but soon realize the challenges that come with it. His relationships with his friends could be affected. Some might be worried about the change in him, while others might encourage him to master the symbiote's power. He would have to learn self - control and discipline in a whole new way. His journey would involve not only mastering the physical abilities of the symbiote suit but also maintaining his positive and determined personality. He'd need to find a balance between using the symbiote's power for good and not succumbing to its possible negative influences, which would be a great test of his character and growth.
Occasionally, Spider-Man does get the symbiote suit back. It depends on the specific comic series and plotlines. In some cases, it's to introduce new challenges or developments for the character.
The symbiote could make Naruto's relationships more complicated. For her friends, they might be initially scared or distrustful of the new - looking Naruto with the symbiote. For example, Sasuke might see her as a threat now. But as they learn that the symbiote is actually helping Naruto control the Kyuubi, they might slowly accept it.
A plot idea could involve the symbiote suit being able to communicate with other symbiotes from outer space. It could be luring them to Earth, thinking they can all live in harmony, but they actually want to take over the planet. Spider - Man has to figure out a way to stop this while also dealing with the fact that the suit is becoming more and more unruly as it gets closer to its 'friends'.
The symbiote could make Naruto's ninja way more about adaptation. Since the symbiote brings new physical abilities, Naruto might need to adapt his fighting style. His ninja way of never giving up could be enhanced as he now has to overcome not only his normal challenges but also the challenges of controlling the symbiote. For example, if the symbiote has a weakness to certain elements, Naruto would have to find ways to work around that while still staying true to his beliefs.
The symbiote can change Naruto's physical appearance. For example, it might give him a more menacing look with some black markings similar to traditional symbiote looks in other stories. This can also affect how others perceive him, making some fear or be more cautious around him.
Initially, the relationship could be rocky. Naruto, being used to his own way of life, might find it difficult to adjust to the presence of the fem symbiote. However, as the symbiote reveals its powers and shows that it can help Naruto in his struggle against neglect, they begin to form a connection. The symbiote may start to feel empathy for Naruto's situation, and Naruto may come to see the symbiote as a partner. As they face more and more difficulties together, such as fighting against those who still look down on Naruto, their relationship evolves into a deep and unbreakable bond of mutual understanding and support.
Spider - Man could develop a new sense of confidence, but also arrogance. The symbiote suit makes him stronger and more powerful, so he might start to think he can handle any situation alone. This could lead to him pushing away his friends and allies, like Mary Jane or Harry Osborn, until he realizes the error of his ways.
It could be from a foreign land. Maybe some traveling merchants brought it to the Hidden Leaf Village. They lost it on their journey and Naruto just happened to stumble upon it.