In the fanfiction, they could have a very protective relationship. The brother might always be looking out for Hermione, especially in dangerous situations at Hogwarts. He could be like a secret guardian, using his own unique skills and knowledge to keep her safe.
In the fanfiction, their relationship could be one of mutual admiration. The baby brother could look up to Hermione as a role model, seeing her as a source of inspiration. And Hermione could be in awe of how quickly he picks up new things, like magic spells or concepts, and they could bond over their shared love for magic.
Well, they could be very protective of each other. Hermione, being the intelligent and strong - willed witch she is, might take it upon herself to teach her little brother all she knows about magic. And her little brother could look up to her and be her biggest supporter in Hogwarts, always cheering her on during her academic achievements and adventures.
Maybe they embark on a journey to rescue a captured wizard or witch. They use their different strengths - Hermione's strategic thinking and her brother's charm or ability to make quick friends in the wizarding world - to plan and execute the rescue mission.
In the fanfiction, Hermione and her older sister could have a complex relationship. Maybe the sister is overprotective, constantly looking out for Hermione at Hogwarts, especially with all the dangerous situations she gets into. The sister could also be a bit jealous of Hermione's academic success and magical abilities, which could lead to some sibling rivalry.
He could be really curious. Just like Hermione is always eager to learn new spells and knowledge, he might be constantly exploring the Hogwarts grounds, looking for hidden secrets or new magical creatures.
They might have a really close, protective relationship. His brother could be the one who always has Draco's back. Like when Draco gets into trouble with other students or is under pressure from the Death Eaters, his brother steps in to help him out, even if it means going against the family's traditional views sometimes.
Perhaps the older brother was thought to be dead. But he actually survived and has been living in a far - off magical land. In the fanfiction, his return could be because he sensed that Hermione was in danger. He could have unique magical abilities that are different from Hermione's, like the power to control time in a very specific way. This would add an interesting dynamic to the story as Hermione tries to figure out how to incorporate her brother's abilities with her own knowledge.
His presence could make Hermione more responsible. She might have to take on babysitting duties, which would cut into her study time, but also teach her about time management in a new way. For example, she'd have to find time to study while also making sure her baby brother is safe and happy.
A possible plotline is that the older brother, having graduated from Hogwarts before Hermione, has a lot of connections in the wizarding world. When Hermione starts getting involved in the fight against the Dark Lord, he uses these connections to protect her. He might get her access to powerful protective spells or magical items that are not easily available. He could also be a bit of a maverick and not fully trust Dumbledore. So when Hermione is blindly following Dumbledore's orders, the brother steps in to make sure she's not being led into unnecessary danger. For instance, if Dumbledore sends Hermione on a dangerous mission, the brother might try to find an alternative way to achieve the same goal without putting her in harm's way.
Well, they could have a very protective relationship. Her brother might be overly protective, always looking out for Akeno, especially if she's in a dangerous or tricky situation. For example, if there are some mean characters in their school or community, her brother would step in to defend her.