In a Harry Potter War Museum in fanfiction, there would likely be portraits of the fallen heroes. People like Fred Weasley, who sacrificed his life in the war. There could also be sections dedicated to the different spells used in the war, with explanations and demonstrations of how they worked. And of course, there would be exhibits about the Order of the Phoenix, showing their plans and strategies against Voldemort.
Well, it could include replicas of the Dark Mark. This was the symbol of Voldemort and his Death Eaters. It was a very important and feared symbol during the war. Another thing could be models of the various battlefields like Hogwarts during the final battle. There might also be displays of the different wands used by the important characters, such as Harry's phoenix - feather wand.
It could be organized by the different phases of the war. For example, one section could be about the early days when Voldemort first rose to power. Another section could focus on the time when the Order of the Phoenix was formed and their initial battles. And the final section could be about the grand finale at Hogwarts.
Perhaps in this fanfiction, Harry Potter declares war because he discovers a new and even more dangerous threat that the wizarding world has been ignoring. He realizes that the only way to deal with it is to take a stand and fight. So, he uses his influence and skills to form an army and begins a full - scale war against this new enemy, which might be a powerful dark wizard from a far - off land or an ancient evil that has been awakened.
A plot could be that a group of war veterans somehow end up in the Harry Potter universe. They form a sort of special unit within the wizarding world. They introduce muggle military strategies like guerrilla warfare to combat the Death Eaters. Along the way, they learn about the magical society and how to use magic in their fight. This creates a unique dynamic as they blend their muggle knowledge with the magic of the wizarding world.
In this fanfiction, it might be that the wizarding world is in a state of chaos due to some ancient dark magic being unleashed. Harry, feeling the weight of the situation, starts singing 'This is War' as a declaration of his determination to stop it. His singing could have magical effects, like inspiring the portraits in Hogwarts to come to life and fight alongside him.
Well, in a 'This is war' Harry Potter fanfiction, the main conflict could be between different magical factions. Maybe the Death Eaters have formed an alliance with some dark creatures and are waging an all - out war against Hogwarts and the Order of the Phoenix. They could be fighting over control of the wizarding world, with each side having different ideas about how magic should be used and who should have power.
Harry Potter himself is, of course, a common character. Then there's Hermione Granger, as she was one of Harry's closest friends during the war. Ginny Weasley is also often included, since she had a romantic relationship with Harry. Luna Lovegood might be in there too, with her unique and dreamy personality. Sometimes, characters like Fleur Delacour could also be part of the harem, adding an international aspect to the relationships.
Obviously, James and Lily Potter are key characters. Then there's Dumbledore. He was always involved in important matters, so he might be there to offer his wisdom or protection. Sirius Black could also be a character, as he was Harry's godfather. He might be hovering around nervously, eager to meet his godson. And Hagrid, who later played an important role in Harry's life, could perhaps be there to bring some news from the wizarding world to the Potters.
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.
Well, perhaps in this fanfic, the wizarding world has to face a nuclear threat from the Muggle world. Wizards might use their magic to try and stop the missiles. For example, they could create a huge magical shield around major wizarding cities like Hogwarts. The characters from 'Harry Potter' would be in a race against time, with Harry, Hermione and Ron using their knowledge and skills to find a way to disable the nuclear weapons before they cause destruction. It could also explore how the wizarding society views the Muggle's most powerful weapon and how they interact with the Muggle governments during this crisis.