I really like 'Eclipse'. It focuses on the rebuilding of Hogwarts and how the students and teachers are trying to move forward. It has some really interesting new relationships and character developments that are quite in line with the original Potterverse feel.
Ron is often in the spotlight too. He might be struggling with finding his place in a post - war world. Maybe he's feeling overshadowed by Harry's hero status or trying to make a name for himself in the Ministry. Luna is another character that fanfictions like to focus on. Her unique perspective can bring a lot to the story, like helping to heal those who are still haunted by the war with her dreamy yet wise words.
One great 'Best After the War' Harry Potter fanfiction is 'The New Beginning'. It shows how the characters are rebuilding their lives after the war. The relationships are explored in a really interesting way, especially Harry and Ginny's as they start their family. Another is 'Rebuilding Hogwarts' which focuses on the restoration of the school and how the students and teachers come together to make it better than ever.
It could be Ron. Maybe he starts to feel that Harry has changed too much after the war and is no longer the friend he once knew. He might be influenced by outside forces or his own insecurities. Another possibility is Hermione. If she gets too involved in the new Ministry politics and starts to believe that Harry's actions are not in line with the new wizarding order, she could turn on him.
Perhaps Harry meets magical creatures that are rarely seen by wizards. Since he is out exploring after the war, he might stumble upon a group of centaurs who have their own unique wisdom about magic and the future. He could also encounter veelas, and through his interactions with them, learn more about the different cultures within the magical world. There's also a chance he meets other young wizards who are on their own adventures, and they form a sort of traveling group together.
In such a fanfiction, Harry might initially struggle with his blindness. Ginny, being the strong - willed character she is, would encourage him to not let it hold him back. There could be a lot of emotional moments between them, like when Harry first realizes he can no longer see Ginny's beautiful face. Ginny, on the other hand, would assure him that their love is not based on sight. They might also encounter difficulties from the wizarding society that doesn't fully understand how to deal with a war - hero - turned - disabled, but they would face it all together.
I'd say 'The Quest Beyond'. In this fanfic, the characters embark on a journey to find a powerful magical artifact that was lost during the war. Along the way, they encounter all sorts of obstacles and enemies, making it a real page - turner.
A good 'After Death' Harry Potter fanfiction is 'When Harry Passed On'. In this story, Harry finds himself in a strange in - between world where he can observe the living but not interact directly. It's a very thought - provoking read. Another one is 'Death and the Boy Who Lived'. Here, Harry's death sets off a chain of events that forces the wizarding world to reevaluate their beliefs. And 'Harry Potter in the Aftermath of Death' shows a world where Harry's death has led to a split in the wizarding community, some believing he will return and others accepting his end.
In Harry Potter fanfiction, life after war could be a time of rebuilding. The wizarding world might focus on restoring Hogwarts to its former glory. Wizards and witches would come together to repair the damaged parts of the school, like the Great Hall which may have been scarred during the battles. They would also work on mending relationships. For example, some families who were on opposite sides during the war would try to reconcile. And there could be new magical laws and regulations to prevent another such dark time from occurring.
One possible reason could be that he is suffering from post - traumatic stress disorder. After all he has been through, he might want to isolate himself from the wizarding world to heal. Another reason could be that he feels a sense of guilt for those who died in the war, and disappearing is his way of punishing himself.