The service dog could also play a role in Harry's social life. In the wizarding world, having a non - magical creature as a constant companion might be a bit strange at first. But the dog's loyalty and cuteness win over the hearts of his friends, and it helps Harry form deeper bonds with people like Hermione and Ron, who might initially be a bit skeptical.
One possible storyline could be that the service dog helps Harry deal with his PTSD from all the traumas he faced, like the death of his parents and the battles at Hogwarts. The dog could sense when he's about to have a panic attack and comfort him.
It could interact with magical creatures. Perhaps it befriends the house - elves at Hogwarts. The elves might take care of the dog when Harry is busy, and the dog, in return, shows them unconditional love, which is something the elves rarely experience from the wizards.
Another storyline could involve the sister being in a different magical school all this time. When she discovers Harry's situation, she transfers to Hogwarts. She then tries to fit into the Hogwarts environment while also trying to figure out how to use her knowledge from her previous school to aid Harry. She might bring new ideas about magic that are different from what they teach at Hogwarts.
One possible plot could be that Harry has some sort of post - war trauma from all the battles he's been through. The service dog could be trained to sense his panic attacks and help him calm down. For example, when he has nightmares about Voldemort, the dog wakes him up and stays by his side until he feels better.
Perhaps the daughter inherits some unique magical abilities from both her parents. Harry's ability to face Voldemort fearlessly and Draco's cunning and resourcefulness could combine in her. She might use these skills to solve mysteries around Hogwarts. Like, there could be an ancient magical artifact that has been lost for centuries and she, with her combined traits, is the only one who can find it. And in the process, she discovers more about the history of Hogwarts and how her parents' pasts are intertwined with it.
Well, it could be a guide. Maybe the dog knows secret passages in Hogwarts that Harry is unaware of. The dog could lead Harry to these places, which might hold important clues or magical items. Also, the dog could be a friend in a more tactile way than Hedwig. Harry could play with it and it could provide emotional support during tough times at Hogwarts, like when he's facing difficulties with exams or dealing with bullies.
One possible storyline could be that their daughter inherits both Harry's courage and Hermione's intelligence. She might face a new threat at Hogwarts that combines elements of old dark magic and new, unknown forces. Maybe she discovers a hidden chamber that holds secrets about their family's past, leading to an adventure filled with mystery and danger.
One interesting storyline could be that Harry discovers his moon powers during a full moon at Hogwarts. Maybe he can communicate with magical creatures that are only active during the full moon. Another could be that his moon powers are linked to a hidden prophecy, and Voldemort wants to steal those powers for himself.
One interesting storyline could be that his younger siblings are sorted into different houses at Hogwarts. For example, one might be in Hufflepuff while Harry is in Gryffindor. This could lead to some sibling rivalry as well as moments of them coming together to face challenges. Another could be that his younger siblings have unique magical abilities that Harry doesn't possess, and they end up helping him in unexpected ways during his battles against Voldemort.
Well, a storyline could revolve around the mystery of her blindness. Maybe it was caused by a dark spell when she was a baby, and as the story progresses, Harry and his friends try to find a way to reverse it. Meanwhile, she is learning to be independent and strong. She could also form a special bond with some magical creatures that are attracted to her unique situation. For instance, a thestral might befriend her because she can sense its presence without seeing it in the normal way.
Perhaps a fanfiction could show Harry's relationship with his professors in a new light. Some professors, like Professor Snape, might initially be unsympathetic, seeing it as a Muggle weakness. But as the story progresses, they could come to understand the gravity of his situation and help him in their own ways. Dumbledore, on the other hand, could use his wisdom to guide Harry in accepting his condition and still being a great wizard.