A possible plot could involve a dark wizard from the Harry Potter world teaming up with a powerful sea - based villain in the ship girl world. Harry has to form an alliance with the ship girls to stop them. Along the way, he discovers that there are hidden magical elements in the ship girl world that are connected to his own magic. He then uses this knowledge to strengthen the bond between him and the ship girls and ultimately defeat the villains.
Perhaps the ship girls start to show signs of magic abilities similar to those in the Harry Potter world. Harry is called upon to train them and help them control these new powers. In the process, they uncover a conspiracy that threatens both the ship girl world and the wizarding world. Harry and the ship girls then embark on a journey to stop this conspiracy, facing many challenges along the way and growing closer as a team.
One plot idea could be that a former Hogwarts student, who was bullied and humiliated, returns as the 'fallen one' with newfound dark magic powers. They start by targeting their old bullies and then expand their revenge to the whole school, causing chaos in Hogwarts. Another could be a wizard who was wrongly accused of a crime and lost everything. Now, they want revenge on the Ministry of Magic and those who wronged them. They might start a secret rebellion using dark and forbidden magic.
Sure. Maybe Harry is raised by Tony Stark in particular. Stark tries to understand Harry's magic and even uses some of his technology to enhance Harry's magical items. For example, he modifies Harry's wand to be more powerful. When Harry is old enough, he wants to go to Hogwarts, but the Avengers are hesitant because they don't know what kind of place it is. This creates a conflict. Or perhaps an alien race attacks both the magical world and the Muggle world, and Harry has to bring the two worlds together to fight the common enemy.
Maybe they get transported to a strange new dimension where the rules of both their worlds are all jumbled up. They have to rely on each other to survive and find their way back home. During this time, they encounter strange creatures that are a mix of magical beasts and Greek monsters. And as they face these challenges, they grow closer as brothers and become even more powerful as individuals.
Perhaps Voldemort discovers Harry's connection to Lady Sif and tries to use it to his advantage. He might try to steal some Asgardian magic or artifacts related to Harry's heritage. Harry then has to stop Voldemort while also dealing with the new - found knowledge of his mother and the Asgardian world.
One plot could be that Harry Potter is bitten by a vampire during one of his adventures outside Hogwarts. He then has to struggle with his new vampiric nature while still trying to protect the wizarding world from dark forces. Another idea is that there is a hidden vampire community within the wizarding world that Harry discovers, and he has to deal with the politics and secrets there.
One possible plot could be that Ash finds an injured Zorua and decides to take care of it. As Zorua heals, it forms a strong bond with Ash and starts to accompany him on his Pokémon journey. They might face a trainer who specializes in dark - type Pokémon and Zorua has to use its skills to help Ash win the battle.
Well, it could be that '13' is an alien entity that crash - lands near a river on Earth. The fanfic could then explore how this alien, which is completely out of its element, tries to adapt to the new environment around the river. It might encounter local wildlife, humans, or other strange phenomena related to the river. Another plot could be that '13' is a cursed object or person, and the river has the power to break the curse. So the story would revolve around '13' trying to reach the river and overcome the obstacles in the way to be freed from the curse.
One idea could be that Harry Potter is on a mission for the wizarding world that somehow leads him to cross paths with a member of the Windsor family. They initially don't get along because of their different backgrounds, but as they spend more time together, they start to fall for each other. Harry could show the Windsor character some of the magic of his world, like taking them on a broomstick ride over the countryside.
Well, in such a fanfic, Harry Potter might find himself in a world where ship girls exist. He could use his knowledge of magic to protect the ship girls from threats. For example, he could cast protective spells around their ships. Also, he might learn about the unique cultures and technologies related to the ship girls, and perhaps even introduce some of his wizarding world elements to them, like using magic to repair their ships faster.
A possible plot could be that Mr. Potter is always the first to volunteer for a dangerous mission in Hogwarts. However, in this fanfiction, 'not this time'. He hesitates because he has a premonition or he's dealing with some personal issues that make him less confident. This causes a stir among his friends and enemies alike, and other characters might step up or try to force him to take on the task anyway, leading to a complex web of relationships and power struggles.