In a fanfiction where Harry is abandoned as a child, there could be a plot where he is left at the doorstep of a powerful magical family other than the Dursleys. This family initially rejects him but then realizes his potential and decides to train him in the ways of dark magic, which he then has to struggle with as he grows up. Another idea is that Harry is abandoned in a magical forest. There, he is raised by magical plants and animals. He develops a special connection with them and uses this connection to create a new form of magic that no one in the wizarding world has ever seen before. Also, he could be abandoned near a wizarding school in another country, and he grows up learning different magical traditions and brings these new ideas back to Hogwarts when he finally returns.
Well, perhaps in this fanfiction, Harry is abandoned as a child and is then taken in by a dark wizard who has his own motives. Maybe the dark wizard wants to use Harry's fame to gain power in the wizarding world. Or it could be that Harry is abandoned and ends up in a parallel magical dimension where he has to find his way back to the normal wizarding world while learning new and strange magics. Another angle could be that he is abandoned and is found by a magical creature, like a centaur, who imparts wisdom and unique magical abilities to him.
One idea could be exploring the alternate timelines more deeply. For example, what if Voldemort had actually won in one of those timelines? How would the wizarding world look like? Another could be delving into the relationship between Albus and Scorpius in a more complex way, like their adventures outside of Hogwarts that test their friendship.
One idea could be that the second child discovers a long - forgotten magic spell that has the power to reverse time briefly. This could lead to some interesting adventures where they try to correct past mistakes in the wizarding world. Another idea is that the second child has a special connection with magical creatures that no one else does, and they use this connection to solve a mystery involving a dangerous creature that is threatening Hogwarts.
Some fanfictions might focus on the relationship between Albus and Scorpius in more depth. Maybe they discover a hidden magical bond between them that gives them unique powers, and they have to keep it a secret from everyone else while trying to use it to solve a mystery in Hogwarts that the teachers can't seem to crack.
In the Harry Potter series, Voldemort was an abandoned child. Voldemort's mother, Merope, made an aphrodisiac to make Riddle elope with her and have a child (Voldemort), but after stopping the drug, Riddle woke up and abandoned Merope. Merope could only give birth to the child alone at the entrance of the orphanage and died soon after. Voldemort grew up in the orphanage and did not feel the love of his family and the love of his peers. Harry Potter and the Goblet of Fire was not enough. Everyone, please click to read the novel!
A possible plot could be that the child is sent back in time accidentally. In the past, they have to use their knowledge of modern magic (which is different from the magic of that time) to survive and also make sure not to change history too much. Along the way, they learn more about their family's history and the roots of the wizarding world that their parents might not even be aware of.
One interesting idea could be the exploration of how the secret child discovers their magical heritage. For example, they might start showing accidental magic and then begin to piece together their connection to Harry Potter. Another idea could be the child facing unique challenges in the wizarding world that are different from what Harry faced, like dealing with the expectations of being Harry's child in a more modern and changed wizarding society.
In some 'Harry Potter child soldier fanfiction', there might be a new dark force that forces the Ministry of Magic to consider using child soldiers. This could lead to a lot of internal conflict within the wizarding community. Some might oppose it on moral grounds, while others might see it as a necessary evil to protect their world. And it could change the relationships between characters as they take sides on this controversial issue.
Well, in 'Harry Potter child services fanfiction', a cool aspect could be the interaction between child services and magical creatures related to children. For instance, if a child has a special bond with a hippogriff or a house - elf, child services might have to step in to ensure the safety of both the child and the creature. Also, they could be involved in cases where a child's magical abilities are so strong that it becomes a danger to themselves and others, and they'd need to find ways to control and train those abilities.
One idea could be exploring the relationship between the new character, the Demons Child, and the existing Hogwarts students. Maybe the child has unique powers that both intrigue and frighten others.
One idea could be a story where a young wizard from the Harry Potter world accidentally travels to the Bleach universe. He could discover his newfound spiritual powers and try to find a way back home while getting involved in the battles against Hollows. Another plot could be a crossover where the Hogwarts houses are somehow related to the different Soul Reaper squads in Bleach. For example, Gryffindors could have an affinity with the more combat - oriented squads.