In fanfiction, Harry Potter taking his money and leaving could lead to him becoming a sort of magical entrepreneur. He could invest his money in new magical inventions or start a business that helps underprivileged wizards. For example, he might use his wealth to open a school for those who can't afford to go to Hogwarts, teaching them basic magic skills and life lessons. This would not only give him a new purpose but also make a significant impact on the wizarding community at large.
Hermione could be the one. With her vast knowledge of the wizarding laws and her sharp intellect, she might dig up some old regulations that prove Harry's right to his money. She would then fight tooth and nail in the wizarding courts or against the goblins at Gringotts to get his money back.
Well, in this fanfiction 'harry potter takes his lordship', it could potentially revolve around Harry's journey as he accepts this new lordship. Maybe he has to make difficult decisions regarding the wizarding community. He might face opposition from those who don't want him to have this new - found power. And he'll probably have to use his skills and knowledge, both magical and otherwise, to navigate this new phase in his life. It could also explore how his relationships with his friends like Ron and Hermione change as a result of this new status.
In some fanfictions, Harry might hide his money in a secret compartment of his trunk. He could use magic to create a hidden space where no one else can find it.
Harry Potter could use his money to improve Hogwarts in fanfiction. He might donate to renovate old classrooms, buy new equipment for the library or even fund extra - curricular activities for students. After all, he has a strong connection to the school and wants to give back.
Maybe he discovers some legal loophole in the wizarding world's financial system that allows him to reclaim his inheritance. For example, if there was some improper handling of his family's vault by the goblins at Gringotts, he could use that as a basis to demand his money back.
In fanfiction, 'Harry Potter takes his owls early' could potentially be a plot twist. It might mean that Harry is showing his eagerness or perhaps there are special circumstances forcing him to take this step earlier than usual. Maybe it's related to some impending danger or a unique opportunity he doesn't want to miss.
Obviously, Harry Potter is one of the main characters as the title suggests. There might also be characters like Hermione and Ron, his best friends, who would likely be involved in his journey with this new lordship. And perhaps some other characters from the original Harry Potter series like Dumbledore (if it's set in that time frame) or other members of the wizarding community who have an interest in this new development in Harry's life.