There could also be interactions with the new generation of ninjas. They might view Obito as a sort of legend or a cautionary tale. Their fresh perspectives could either inspire Obito to change further or make him feel even more out of place in this new post - war ninja world.
Well, in this kind of fanfiction, Obito might face a lot of challenges in readjusting to the post - war world. Maybe he has to deal with the guilt of his past actions.
In such a fanfiction, Obito might seek redemption. He could use his remaining powers to help rebuild the villages he once damaged. Maybe he would start by teaching the new generation about the true cost of war and how to avoid the same mistakes.
In the 'Obito alive after war fanfiction', the world would see some major changes. Firstly, Obito's survival could lead to a shift in the moral compass of the ninja world. His story of redemption (if there is one) could inspire others to forgive and move forward. Secondly, his combat abilities could be used to train a new generation of ninjas in a more comprehensive way. He could teach them about the importance of not only physical strength but also mental strength. Moreover, his presence might also lead to a re - evaluation of the history of the ninja wars, as he has been involved in many significant events.
One possible plot could be that Natsu returns with newfound powers. He might use these powers to help rebuild the world after the war, and also to reunite with his friends. Maybe he has to face some remnants of the enemy forces that still lurk in the shadows.
Maybe it's an old enemy who survived the war and has grown stronger. They hold a grudge against Natsu and his friends and are now seeking revenge. For example, if there was an enemy that was thought to be defeated before the war but managed to survive and is now back with a vengeance.
Well, perhaps Ash returns physically but is emotionally scarred. Serena would be there to comfort him. They could start by just reminiscing about old times. Then, Ash might introduce Serena to some of his war - time comrades who are also Pokémon trainers. This could lead to a whole new set of storylines involving group adventures, Pokémon battles, and the rebuilding of relationships that were strained during the war.
Naruto could be one of his allies. Naruto has this knack for seeing the good in people and would probably be willing to give Obito a chance to redeem himself. Also, Sakura, with her skills as a medic - ninja, could be an ally. She might help heal Obito if he was injured during the war and see the potential in him to be a force for good.
Their relationship could become deeper. Ash has been through a war, and Serena's support during his return would make their bond stronger. They might be more reliant on each other.
In such a fanfic, perhaps Obito could use his Sharingan powers in new and unexpected ways after the war. He might start to see the world differently and strive to make amends for his past actions. He could use his abilities to help rebuild the villages he once tried to destroy, like Konoha.