A custom staff could also make Harry more responsible. If the staff is very powerful, he would need to be careful not to misuse it. This would lead to him being more cautious and thinking more about the consequences of his actions, which in turn would shape his character in a more mature way.
The staff could make him more confident. If it has powerful magic, he would feel more capable of taking on difficult tasks. So, his character might shift from being a bit hesitant to more assertive.
First, think about the function of the staff. If you want it to be a defensive weapon, it could emit a force field when the user utters a specific incantation. For the design, it could have carvings of the constellations on it, symbolizing its connection to the celestial magic. Also, consider the history of the staff. Perhaps it was crafted by an ancient wizard who used it to defeat a powerful dark lord long ago.
One idea could be a staff that has the power to control the elements. For example, it could summon rain to put out fires or create strong winds to disperse dark creatures. Another interesting custom staff could be one that can translate any magical language. This would be really useful for characters when they encounter ancient spells or texts from different magical cultures.
If Harry Potter gets a custom staff in fanfiction, it could be a key element in a new adventure. Maybe the staff was created by a long - lost wizarding group, and in order to fully understand and master it, Harry has to embark on a journey to learn about the group's history and magic. This could lead to him uncovering secrets that are important for the whole wizarding world.
It could be Dumbledore. Dumbledore is always full of surprises and he might give Harry the staff as a last - resort weapon to fight against Voldemort. He could have been secretly researching the staff and its powers and decided that Harry was the only one who could wield it properly.
Harry Potter himself could be the main character. Given his central role in the original series, it would be natural for him to be involved with the mysterious metal staff. He could be on a quest to understand the staff's true power and how it can be used to defeat the new threats emerging in the wizarding world.
The characters could be initially curious about the staff. For example, Hermione might be eager to study it, to understand its magic which is so different from what she knows. Harry, on the other hand, might be more cautious, sensing the dark power within it.
There's a chance that the maker is a new character, an old hermit wizard who lives deep in the Forbidden Forest. He has been observing Harry from afar and realizes that the wands available in the regular market are not sufficient for him. So, he uses his knowledge of forgotten magics to craft a custom wand just for Harry.
She could start as a naive and curious girl. As the story progresses, through her experiences with the Staff of Merlin, she becomes more confident and powerful. For example, when she first touches the staff, she might feel a strange power but not know how to control it. Then, with the help of some magical training, she starts to master it.
It could make him seem more edgy and less reliant on magic. Instead of always reaching for his wand, he'd have the option of the gun. This might make him appear more dangerous to his foes.