Well, it could be that Naruto is really confused at first. He might find the ideas in the fanfiction very strange, like the new powers of immortality described. Maybe he starts to question his own understanding of the ninja world.
Perhaps in this 'naruto reading the first immortal fanfiction' scenario, the fanfiction is actually a prophecy in disguise. Naruto, not realizing it at first, starts to notice that some of the events in the fanfiction seem to be related to things that are starting to happen in the real ninja world. He then feels a sense of urgency to understand the rest of the fanfiction to prevent any disasters or to bring about a new era of peace. He might go on a journey to find the author of the fanfiction, believing that they have some kind of special knowledge or power.
One tip is to first understand the basic Naruto universe. This includes knowing the main characters, their abilities, and the different villages. It helps you better appreciate the fanfiction. Another is to look for well - rated fanfictions. High ratings often indicate that other readers have enjoyed the story.
An immortal OC can also impact the plot by being a source of information. Having lived through so much, they know the secrets of the past, including things about the origin of chakra or the true nature of certain clans. This knowledge can be a driving force for the main characters' quests and can completely change the narrative as they uncover things that were previously hidden.
Well, one possibility could be that Naruto somehow gets transported to the DC universe where the Immortal Justice League exists. Maybe he teams up with them to fight a common enemy like Darkseid or some other powerful villain. Naruto's unique jutsu and combat skills would add a new dynamic to the League's battles.
One possible plot could be that Naruto, being immortal, has seen many things in his long life. He comes to the X - Men universe with a different perspective. He might initially be seen as a threat because of his unknown powers. As the story progresses, he could prove himself useful by helping the X - Men in a big crisis. His immortality would allow him to take risks that others can't, and this could lead to some very exciting storylines. For example, he could sacrifice himself in a way that he knows he'll come back, to save the X - Men from a powerful enemy. This would earn him their trust and he could then start to explore the mysteries of the mutant world further.
Well, in this fanfiction, Naruto's immortality could lead to him being a sort of legend in the Pokemon world. He might start a new ninja - Pokemon fighting style. He'd use his shadow clones to train multiple Pokemon at once. And his immortality would mean he could face any danger in the Pokemon world without fear of death. This could attract the attention of the Pokemon League, who would be both intrigued and a bit worried about this new and powerful trainer.
Well, perhaps Naruto, with his immortality, would bring his ninja skills to Hogwarts. He might teach the students some unique combat moves, or get involved in battles against dark wizards using his Rasengan and shadow clone techniques.
In the 'naruto is an immortal child fanfiction', it could be that Naruto's immortality is a curse rather than a blessing. He is forever trapped in a child's body, unable to fully experience adult life. He might struggle with his identity as he is different from everyone else. He could then embark on a journey to find a way to either end his immortality or find a purpose for his eternal existence.
The plot might involve Naruto trying to find a way back to his own universe while getting involved in the affairs of the DC Universe. He could use his ninjutsu to fight against supervillains. Also, his immortality would give him an edge in long - drawn battles and he could form interesting relationships with DC characters like Batman, who might be intrigued by his abilities.
Another plot twist might be that Naruto reads a future where the entire ninja world is in ruins. This could lead him to take extreme measures in the present to prevent that future from happening. He might try to unite all the ninja villages in a way that has never been done before, facing many obstacles along the way as different villages have their own interests and grudges.
One popular plot twist could be Naruto using his immortality to learn and adapt Gundam technology in ways no one expected. For example, he might infuse chakra into the Gundam's systems, giving it an edge in battles. Another could be a Gundam pilot having a connection to Naruto's world through some ancient relic, leading to a crossover of their powers and knowledge.