One interesting storyline could be Hermione getting involved with the Black family secrets. Maybe she discovers a hidden Black family magic that could change the wizarding world. For example, she might find a spell that has been lost for centuries within the Black family library.
Another idea is Hermione befriending a member of the Black family who is an outcast. This outcast could introduce Hermione to a different side of the family's history, one that's not as well - known. They could work together to redeem the family's name in the wizarding community.
Perhaps a storyline where Hermione is a mother in a post - war wizarding world. She has to raise her children in a society that is still rebuilding, teaching them values of peace and unity. This could involve her sharing her own experiences from the war to instill important life lessons.
One interesting storyline could be Hermione finding herself in Gotham City and having to use her magical skills to outwit the Joker. Maybe she tries to stop his evil plans without revealing her magic to the non - magical inhabitants of Gotham. Another could be the Joker getting his hands on some magical item from Hermione's world and she has to retrieve it. For example, if he got a powerful wand, Hermione would need to use her intelligence and magic to get it back before he causes chaos with it.
One interesting storyline could be where Deadpool somehow gets transported to the wizarding world. He'd be his usual chaotic self, confusing the hell out of everyone, especially Hermione. She might initially be put off by his insanity but gradually see his good side as he helps in some sort of magical - mutant mash - up adventure, like fighting a new dark wizard - mutant hybrid villain.
Well, there are storylines where Hermione discovers some long - lost knowledge of Regulus that helps her in her fight against Voldemort. Maybe she finds a secret spell or a hidden artifact that Regulus had been protecting. And then there are those fanfictions where they are brought together by a prophecy that only they can fulfill. It often involves a lot of mystery - solving and adventure as they figure out what the prophecy means and how to act on it.
One possible storyline could be that Alphard Black, through some magical means, leaves behind a diary or a magical object that Hermione discovers. This object could hold secrets about the Black family's past that Hermione is eager to uncover, leading to a series of adventures as she tries to piece together the history. Another could be that Alphard's spirit is somehow bound to Hogwarts, and Hermione, being the inquisitive witch she is, stumbles upon his presence and they form an unlikely friendship. He could then guide her in understanding some of the darker magic that was once practiced by the Blacks.
Another storyline might involve Ginny and Hermione teaming up to solve a mystery within Hogwarts. Maybe there are strange disappearances of students and they use their combined skills, Ginny's Quidditch - related quick thinking and Hermione's vast knowledge, to get to the bottom of it. They might suspect a hidden chamber or a rogue spellcaster. They start by interviewing students and staff, gathering clues from different parts of the castle, and finally unmask the culprit.
One possible storyline could be that in a hidden corner of Hogwarts, Snape discovers Hermione's secret project related to advanced potions. This could lead to a begrudging respect as he sees her intelligence and determination, similar to how he respected Lily. Another could be Hermione stumbling upon Snape in a corner where he is reminiscing about his past, and she gains a new understanding of his character.
Another storyline might involve a time - travel scenario where Hermione goes back in time and encounters a younger Fenrir Greyback. She attempts to change his path, to prevent him from becoming the cruel werewolf he is known to be in the future. This could involve her using her knowledge and magic to offer him a different future, but facing many challenges along the way.
One interesting storyline could be their children starting at Hogwarts and facing new, unforeseen magical challenges that Harry and Hermione have to guide them through. Maybe a new dark wizard is on the rise and their kids are the ones who first notice the signs.
A great storyline could be the daughter having a unique magical ability that neither of her parents have. This could lead to her being both feared and admired at Hogwarts. In some fanfictions, she uses this ability to solve mysteries around the school. There could also be a story where she has to choose between following the Slytherin or Gryffindor values more closely, as she has a connection to both through her parents. This internal struggle can make for a very engaging read. And of course, a plot where she gets involved in a time - travel adventure related to her parents' Hogwarts years would be really exciting.