Write a 'Harry is angry and fights back' fanfiction.

His friends like Ron and Hermione would surely be his allies. They have always been by his side in the original stories, so it's likely they'll be there in the fanfiction too, helping Harry in his fight.

Well, it could be that Harry is facing some new dark forces in the fanfiction. Maybe he discovers a hidden group of dark wizards who are plotting against Hogwarts, and he decides to fight back to protect his school and friends.

Perhaps the wizarding government or authorities were being unjust. For example, if they wrongly accused Harry of a crime he didn't commit, his sense of justice would be outraged. His anger would drive him to fight back and prove his innocence. He's not the type to let false accusations stand.

There could be a group of rogue witches and wizards who are against the current system in the wizarding world. They oppose the Ministry of Magic's rules and see Harry Potter as a symbol of the establishment they want to overthrow, so they become the antagonists.

Maybe Harry Potter discovers a new dark threat in the fanfiction and has to fight it using his magical skills and the support of his friends. He could be facing a powerful dark wizard who has found a way to break through Hogwarts' defenses.

Perhaps in this 'harry fights back fanfic', Harry discovers some new powers or spells that he uses to fight back. He could be tired of being pushed around by Voldemort's followers or other bullies in the magical community, and he uses these newfound abilities to protect himself and his friends. For example, he might learn an ancient spell from a hidden book in the restricted section of the library. This spell gives him an edge in combat and he starts to turn the tables on his adversaries.

Obviously, Harry Potter himself. He's the main character who is going to fight back.

Another reason could be that Harry sees the Order as being too cautious or old - fashioned in their approach to fighting Voldemort. He might believe that their traditional methods are not enough to defeat Voldemort quickly and effectively, and this lack of progress makes him angry at them.

Maybe he feels that the Order is keeping secrets from him. In many fanfictions, Harry can be a character who values honesty and when he discovers that the Order, which he may consider an ally, is hiding things from him, it can make him angry.

I'm not sure specifically as there could be many different versions of such fanfiction. It might be about a character named Bella who decides to fight back against some sort of antagonist, perhaps in a fantasy or science - fiction setting.