A third theme could be self - discovery. Through the process of raising his child alone, Harry discovers new aspects of himself. He might learn that he has more patience or that he can be a better cook (using magic of course) than he thought, which helps him grow as a person and as a father.
One common theme is sacrifice. Harry often has to sacrifice his own desires or time for his child. For instance, he might give up on a dangerous but exciting adventure to be there for his kid's first day at Hogwarts.
Another theme is the power of love. Despite being a single father, his love for his child gives him the strength to face any difficulties, whether it's dealing with dark wizards or just the normal problems of raising a child in the wizarding world.
One common theme is the struggle of balancing the magical and non - magical worlds. Harry wants his daughter to be part of the wizarding world but also understand the Muggle world. Another theme is protection. He has to protect his daughter from dark forces that might be interested in her because of her relation to him. And there's also the theme of family, as Harry tries to create a loving family environment for his daughter on his own.
One common theme is sacrifice. James has to sacrifice his own desires and time to focus on raising Harry alone. Another theme is love. His love for Harry is unconditional and drives him to do whatever it takes to protect and raise him well.
One common theme is mystery. Since it's just a single night, there could be a lot of unknown things happening. For example, a character might discover a secret passage in Hogwarts during one night. Another theme is friendship. Friends could support each other through a difficult or exciting single night. For instance, Ron and Harry helping each other during a spooky night in the Forbidden Forest.
Another theme is the growth of the relationship between Harry and his child. Often, at the start, there are difficulties due to the absence of a second parent, but as the story progresses, they develop a strong bond. For example, in some fanfics, they start to understand each other better through shared hobbies or experiences. And this bond becomes the core of the story.
The theme of discovery is big. Harry discovers more about his father's true nature, his friends, and his adventures. Another common theme is the re - imagining of Harry's family life. Instead of growing up with the Dursleys, he might have a completely different family environment with his father around. And of course, there's the theme of love, as the father - son bond is explored in different and often heart - warming ways.
One common theme is the struggle of balancing ninja duties and fatherhood. Naruto has to be out there protecting the village but also be there for his child.
One common theme is redemption. Sirius' father may have been a strict or even cruel figure in the original story, but in fanfiction, he could be seeking redemption for his past actions towards Sirius. Another theme is legacy. How does the Black family legacy affect the relationship between father and son? It could be a burden or a source of pride.
Family acceptance is another theme. Harry has always been an orphan, so in these fanfictions, when he gets a father figure, there's a lot about him learning to accept this new family member and vice versa. It's about building that bond of family that Harry has always longed for.
One common theme is the passing on of magical heritage. The father, often with more experience in the wizarding world, teaches his daughter about spells, potions, and the history of magic. Another theme is protection. Given the dangerous elements in the Harry Potter world, fathers are usually depicted as very protective of their daughters. For example, they might be worried about dark wizards or magical creatures harming their daughters.
One common theme is protection. The father figure often protects Harry from various threats, whether it's dark wizards or the pressures within Hogwarts. Another theme is guidance. They help Harry make decisions and understand the wizarding world better.