Perhaps the child is interested in German history and Germany, as a character in the fanfiction, becomes the child's guide through time. He takes the child to historical sites like castles in Bavaria and tells the tales of knights and kings that once lived there, making history come alive for the young reader.
One possible storyline could be that the child is a new immigrant in Germany and Germany (personified) helps the child adapt to the new culture, showing the child around, introducing local traditions and foods. For example, taking the child to a traditional German Christmas market.
One interesting storyline could be the Teen Titans protecting the child reader from a new supervillain in town. They might take the child under their wing, teaching them about courage and friendship along the way.
One could be about Germany being super protective. He makes sure the reader has a balanced diet, like preparing traditional German healthy meals. He also might be very organized about the baby's future, setting up a nursery with precision. Another storyline could involve him taking the reader on gentle walks in the German countryside, sharing stories of his own upbringing to bond with the unborn child.
Another storyline could be about the child's relationships within the Hidden Leaf Village. Growing up as the child of Naruto (the Hokage) and Hinata, there would be a lot of pressure and expectations. They might have a group of friends who are both in awe of their parents and also a bit jealous. This could lead to some interesting friendship dynamics, like the child having to prove that they are worthy of their friends' respect not just because of their parents but because of their own character.
One interesting storyline could be Severus growing up in his rather dreary neighborhood and his early encounters with magic. Maybe he discovers a hidden magical place near his home where he can practice spells in secret before going to Hogwarts. Another could be his relationship with his parents, especially how their difficult relationship affects his view of love and family in his early years.
One interesting storyline could be a young Superman and Batman teaming up for the first time in a kid - friendly adventure. Maybe they are trying to stop a group of small - time villains who are stealing toys from all the kids in Gotham. They use their unique powers and detective skills respectively to track down the bad guys and return the toys.
One possible storyline could be the male reader being a new recruit in a group where Raven is also involved. They start off as distrustful of each other due to Raven's mysterious nature. But as they go on missions together, they gradually learn to rely on one another and form a deep friendship that could potentially turn into something more.
One interesting storyline is when the male reader discovers a rare and powerful Pokemon that no one else has seen before. This could lead to a whole adventure of protecting it from those who would misuse it. Another is when the male reader gets transported to a different era in the Pokemon world and has to adapt to the different Pokemon species and training methods of that time.
One interesting storyline could be their child having to hide their powers in a normal school. They'd struggle to fit in while also having the responsibility of their superhero heritage. Another could be the child getting kidnapped by a villain who wants to use their unique genetic makeup for evil.
One possible storyline could be Velvet raising her child in a post - Grimm - invasion world. The child might inherit some of Velvet's unique abilities and have to learn to control them while facing the challenges of a world that's still rebuilding. Another could be a story where Velvet's child discovers a hidden power that has been passed down through generations, leading to an adventure to understand its origin and purpose.
A really interesting plot could be that the child is kidnapped by an old enemy of either Wonder Woman or Batman. The kidnapper wants to use the child to get revenge on the heroes. The child then has to use their wits and the powers they've inherited to escape. Along the way, they might make new friends or discover secrets about their parents' pasts that help them in their journey.