At first, it might be a bit strange. His past self would be confused and a bit scared of this older version of himself. But as time goes on, they would start to trust each other. Naruto would be patient with his past self, and his past self would start to look up to him.
Well, in this kind of fanfiction, Naruto raising his past self could have a huge impact on the overall Naruto universe. He could change the course of many events. For example, he might be able to prevent some of the Akatsuki's earlier schemes by having his past self be more aware. His past self could also grow to be an even stronger ninja faster, as he has the guidance of his future self. This could potentially change the power dynamics in the Hidden Leaf Village and how they deal with external threats.
In this kind of fanfiction, Natsu might have some really interesting interactions. He could try to warn his past self about future challenges or mistakes. For example, he might tell his younger self about a particularly difficult battle and how to better prepare for it.
Well, Sasuke might be shocked at first. He could see his younger self's naivete and it might make him re - evaluate his life choices. Maybe his past self would be in awe of his current power but also disappointed in the path he has taken.
They could also have a philosophical discussion. Past Kratos has a lot of unresolved issues, especially regarding his past deeds. Future Kratos, having had more time to think about it all, could share his insights. For example, he might talk about how he has come to terms with his past and how past Kratos can start that journey too. This encounter could be a turning point for past Kratos's character development.
Well, it could start with Natsu accidentally stumbling upon a time - related magic or a magical artifact that transports him to the time when his past self exists. Then they would meet and there would be a moment of shock and confusion.
In the fanfiction, when Sasuke meets his past self, he might try to change the past. He could warn his younger self about the mistakes he made, like leaving the village and seeking revenge blindly. This encounter could be a chance for him to rewrite his own history and avoid all the pain and suffering he went through.