Well, in a 'harry raises his cousin fanfic', it could involve Harry having to take care of his cousin in a situation where the normal family structure has broken down. Maybe his aunt and uncle are unable to look after the cousin for some reason, like they've been put in a magical coma or something. Harry then has to step up and teach his cousin about the wizarding world, how to handle magic, and also about normal life things like school and making friends. He might face difficulties because his cousin could be resistant to the new world he's being introduced to, or Harry might struggle with his own insecurities about being a good caregiver.
In the fanfiction, Harry might raise his cousin in an attempt to break the cycle of animosity that has always been between them. He could show his cousin a different side of life, full of magic and wonder. Harry could also protect his cousin from the dark forces that are always lurking in the wizarding world, and in the process, his cousin could become a valuable ally to Harry.
I'm afraid I can't recommend any particular 'harry raises his cousin fanfic' right now. However, when looking for good ones, you can check the reviews and ratings on fanfic platforms. Look for ones that have a detailed plot summary and positive feedback from other readers. Also, you can join Harry Potter fanfic communities on social media or forums and ask for recommendations there.
Dumbledore could play a role too. He might be the one who gives Harry the idea in a subtle way. Maybe he sees the potential for Harry's cousin to be an important part of the wizarding community in the future, and by having Harry adopt him, he can ensure that the cousin is guided in the right direction.
Well, clearly Harry is one of the main characters as he is the one taking care of the baby cousin. The baby cousin is also a main character, even if it's a young and not fully developed character yet.
In this fanfiction, Ash would have to be really patient. Baby Pokemon need a lot of care. He might start with teaching them basic things like how to find food in the wild. For example, he could show a baby Pikachu where to find the juiciest berries. And he'd have to protect them from other wild Pokemon that might see them as easy prey.
Maybe Harry's magic gives his cousin a sense of security. If the cousin was always in some kind of danger, Harry could use magic to keep him safe. This would make the cousin less fearful and more adventurous. He could start to explore the world around him more, knowing that Harry has his back with magic. In addition, the cousin might develop an interest in magic himself, which could change his whole perspective on life.
One possible plot could be that Harry, having experienced so much loss and understanding the importance of family, decides to adopt his cousin. Maybe his cousin has also faced some difficult situations, like being neglected at home. Harry takes him in and starts to teach him about the wizarding world, creating a bond that was previously unthinkable between them.
Maybe Harry tries to feed the baby cousin some magical baby food. He could make funny faces to get the baby to open their mouth and eat. It would be really adorable to see the baby's reaction to the new flavors.
It could change the story in many ways. For one, Harry might have more of a reason to stay closer to home. Instead of always being eager to rush back to Hogwarts, he might feel a sense of responsibility towards his baby cousin. This could lead to new storylines where he has to balance his wizarding life and his family life.