One interesting plotline could be Deku having to face off against his classmates in a series of challenges that test not only their quirks but also their teamwork and strategic thinking. Maybe there's a misunderstanding that leads to the conflict.
Deku himself is likely to shine. Given his powerful quirk and his growth throughout the main series, he'll surely put up a great fight against his classmates. Bakugo could also shine as he's always been in competition with Deku and has a very strong quirk.
One interesting aspect could be the different interpretations of the characters' powers. In fanfiction, the author might explore new ways Deku uses his One for All ability against Overhaul's powers. It can also show different battle strategies that might not be in the original manga or anime.
You can try looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. These platforms usually have a wide variety of fanfictions, including ones related to 'Deku vs Overhaul'. Just use their search functions to find what you're looking for.
For Nami, her intelligence and cunning are key. She could use her smarts to get Sanji out of trouble in the fanfiction. Also, her love for money and treasure can add an interesting dynamic. For example, she might convince Sanji to go on a dangerous adventure in search of a valuable item, promising him new ingredients for his kitchen.
It can be developed through shared hobbies in the modern world. For instance, if they both like extreme sports, they could bond over skydiving or surfing. This would not only bring them closer but also show a different side of their characters.
Their relationship in the Zoro x Sanji Christmas fanfic could be presented through a series of challenges and reconciliations. For instance, when they are tasked with getting a Christmas tree for the ship. Zoro wants to just chop down the first tree he sees, but Sanji has very specific requirements. They argue, but then realize that by combining their ideas, they can get the perfect tree. This pattern of arguing and then coming together could be repeated throughout the Christmas celebration, showing the complexity and depth of their relationship.
The main differences are in their expressions and some minor details of personality. In the manga, Deku might seem a bit more intense, while in the anime, he's sometimes presented a bit softer.