One Punch Man is a really popular anime. Fubuki, as a character in it, has a lot of potential for fanfics. In a fanfic about them, it could explore their relationship in new ways. Maybe it could show Fubuki trying to recruit Saitama into her group in a more detailed and different way than in the original story. It could also develop her character further by showing her reactions to Saitama's overpowering strength in unique scenarios.
The fanfiction about Fubuki and Tatsumaki in One Punch Man is alluring because it gives a chance to expand on their characters. Fubuki, with her ambition to be a great hero, can be explored further. Maybe in a fanfic, she overcomes her insecurities related to her sister Tatsumaki's much stronger powers.
One possible plot could be that Fubuki, being frustrated with her lack of progress in terms of power compared to Saitama, decides to train with him. This would lead to a series of comical and at the same time, character - building moments. Saitama would probably give her some really simple but effective training advice that she initially scoffs at but later realizes is genius.
Many One Punch Man fanfics with Fubuki and Tatsumaki focus on their interactions with other characters too. They could be paired with Saitama in some comical or action - packed situations. Like, Fubuki trying to recruit Saitama into her group while Tatsumaki is constantly skeptical of his abilities.
The 'One Punch Man Saitama Story' is quite interesting. Saitama is a unique hero. His physical appearance is rather ordinary, but his power is extraordinary. He trained so hard that he lost all his hair and gained the ability to defeat enemies with one punch. In the story, he has to deal with the hero association which has its own rules and politics. Also, he constantly encounters new threats to the city, yet his way of dealing with them is always the same - one punch. However, his interactions with other characters, like his comical exchanges with Genos, add a lot of charm to the story.
Well, a lot of One Punch Man fanfictions about heroes seeing Saitama are really interesting. Some focus on their initial shock at his power. For example, Genos is always in awe of Saitama's strength in the original work, and in fanfictions, this can be explored even deeper, like how he tries to understand the source of that power.
A possible plot is that the OC is a former enemy of Fubuki who has seen the error of their ways. They try to make amends by helping Fubuki in her quest to become stronger and more respected in the hero community. This could involve training sessions where the OC shares some unorthodox fighting techniques that complement Fubuki's psychic powers. The OC could also have connections to some powerful and mysterious figures in the One Punch Man universe, which could open up new storylines for Fubuki.
The OC can be introduced as a new recruit in Fubuki's group. For example, they could be a young and inexperienced hero who is in awe of Fubuki's powers and leadership. They start by following Fubuki's orders and gradually prove themselves useful in battles.
One way is to explore his life before he became a hero. Maybe he had a normal job and was constantly frustrated with the mundanity of it. This could have been the catalyst for his intense training.