In such a fanfiction, perhaps a major plot point is how Dumbledore trains Harry to face a new and greater threat. It could be a dark wizard more powerful than Voldemort, and Harry has to learn a whole new set of strategies and magic under Dumbledore's guidance. Harry might also develop a deeper understanding of the wizarding world's history and secrets through Dumbledore's teachings, which could be a key part of the plot.
One key plot point could be Dumbledore's true identity being revealed gradually. Maybe Harry starts noticing strange things about Dumbledore that make him suspect he is not just an ordinary wizard but Death itself. Another could be how the prophecy about Harry and Voldemort fits into this new paradigm where Dumbledore is Death. It might change the meaning of the prophecy completely, as Dumbledore - as - Death could have a different intention behind the events related to the prophecy.
It might make Harry more confident. With Dumbledore's training, Harry gains more knowledge and skills, which gives him the confidence to face challenges.
In 'Dumbledore adopts baby Harry fanfiction', an interesting aspect could be how Dumbledore chooses to educate Harry. He might introduce him to different magical cultures and theories much earlier than in the original story. Also, the relationship between Dumbledore and the other Hogwarts staff when they find out he has adopted Harry. Some might be supportive, while others might worry about the potential implications for Hogwarts and the wizarding world as a whole.
A great plot point might be Arwen's perspective on the concept of magic in the Harry Potter universe compared to that in Middle - earth. Since she has a different understanding of magic, her reactions and interactions with the wizards could be really fascinating. For instance, she might be surprised by some of the more 'brute - force' spells used in the wizarding world, while the wizards might be in awe of her more subtle and nature - based elven magic. Another interesting aspect could be if Arwen gets involved in the fight against Voldemort. Her elven wisdom and powers could potentially change the course of the battle in unexpected ways.
Often, a key plot point is Fem Harry's self - discovery. She realizes she can be more than just a Potter. For example, she might find new magical abilities that the Potters were not known for. Another plot point could be her making new relationships. Since she's not bound by the Potter name, she can form friendships with people who would have otherwise been off - limits due to family feuds or alliances related to the Potters. Also, her forging a new identity in the wizarding world is a big plot point. She might choose a new name or a new area of study that has nothing to do with the Potter family traditions.
A really interesting plot could be that Ariana's spirit is trapped in a limbo of sorts. Harry, with his penchant for getting into extraordinary situations, discovers a way to communicate with her. They then work together to free her spirit. Along the way, Harry learns more about Dumbledore's past through Ariana's memories, which in turn helps him in his own battles against the remaining dark forces in the wizarding world.
One possible plot could be Dumbledore taking Harry on a magical tour of Hogwarts. He shows Harry secret passages and tells him stories about the founders. For example, they could visit the Room of Requirement together and Dumbledore could explain how it works. This would not only be an educational experience for Harry but also a chance for Dumbledore to bond with him on a more personal level.
One idea could be Dumbledore misplacing his memories and the students of Hogwarts having to help him retrieve them. It could lead to a series of adventures where they discover secrets about Dumbledore's past that were long forgotten.
A possible plot idea is that the duel is a miscommunication. Dumbledore thinks Harry has been influenced by dark magic, and Harry thinks Dumbledore has turned against him. As they duel, they gradually realize the misunderstanding and work together to find the real source of the problem. Or perhaps it's a time - traveling duel where future - Harry has to duel past - Dumbledore to prevent a dark future.
A really interesting plot point can be when Gamora tries to use her combat skills in the wizarding duels in the Harry Potter world. It's a clash of two different fighting styles - her physical combat against the spell - casting of the wizards.