Well, it could change the plot in many ways. For example, he might get some crucial information from the dead. Maybe he could learn some long - lost jutsu from a dead ninja master, which would make him stronger and help him in battles. Also, he could get some secrets about the Akatsuki's plans from their deceased members, which would give Konoha an advantage.
Maybe it's his father, Minato. Minato has a lot of things to tell Naruto, like more about the Uzumaki clan and how to better use the power of the Nine - Tails. And as his father, their connection is very strong, so it's quite possible that he is among the first dead Naruto talks to.
It varies from one fanfiction to another. Some fanfictions might depict Naruto as dead to introduce a new set of challenges for the remaining characters. For example, if Naruto dies, Konoha might be left vulnerable, and characters like Sasuke or Sakura would have to step up in different ways. But there are also plenty of fanfictions where Naruto remains alive and continues his journey, perhaps facing new and even more dangerous threats than in the original series.
I think Mewtwo would be the most fascinating for Naruto to talk to. Mewtwo is a very intelligent and powerful Pokemon. It has complex thoughts about its existence and purpose. Naruto, with his own struggles and growth in the ninja world, could have deep philosophical discussions with Mewtwo. They could exchange ideas about power, identity, and what it means to be different in their respective worlds.
In fanfiction, the possibilities are almost endless. Regarding Naruto being able to summon the dead, it can be a really cool concept. It allows for some deep exploration of the Naruto lore. For instance, he could summon the founders of the ninja villages to learn about the true origins of ninjutsu. This could also create some really emotional moments as he might summon his parents or other loved ones who have passed away, leading to heart - warming or heart - wrenching scenes.
In fanfiction, the possibilities are endless. Naruto could potentially bring back the dead if the writer wants to explore themes of second chances, redemption, or the consequences of messing with the natural order. For instance, if Naruto brings back Sasuke from the dead, it could lead to a whole new arc where Sasuke has to come to terms with being brought back and how it affects his relationships with others. It could also create conflict within the ninja community as some might see it as a dangerous precedent.
Kakashi could be another important character. As a mentor figure, he might be guiding the younger generation through the difficult times after Naruto's death, using his experience and wisdom to keep the village stable.
It might change his relationships. He could communicate with the ghosts of fallen comrades or enemies. This would give him a unique perspective. Maybe he could understand the motives of former villains better and find ways to prevent future conflicts. Also, it could make his bonds with his living friends even stronger as he shares what he learns from the ghosts.