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.
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.
Some fanfics also explore Tatsumaki in different settings or scenarios. Like what if she had to face an enemy that was immune to her psychic powers? Or what if she was transported to a different dimension? These types of 'what - if' scenarios are quite popular in Tatsumaki fanfics as they allow for a lot of creativity and exploration of her character in new situations.
One possible plot idea could be that Tatsumaki gets injured during a battle and Saitama has to take care of her. This would force them to interact closely and start to understand each other better. Another idea is that they are both chosen for a special mission together. Along the way, they face various challenges that require their combined powers. Tatsumaki might initially be dismissive of Saitama, but as they work together, she realizes his true strength and value. This could lead to the development of a deeper relationship between them.
You can start by looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. There are often many One Punch Man fanfics there, including ones focused on Tatsumaki. Just search for 'One Punch Man Tatsumaki' in the search bar, and you'll get a list of relevant stories.
One idea could be Saitama and Tatsumaki teaming up to face a new, extremely powerful villain that even Saitama has trouble with at first. Maybe this villain has the ability to manipulate reality in a way that nullifies Saitama's strength for a short time, and Tatsumaki has to use her psychic powers to protect Saitama while he figures out a way to overcome this new obstacle.
When writing their character dynamics, consider their powers. Saitama's physical strength is limitless, while Tatsumaki's psychic powers are vast. This can lead to interesting situations. For instance, Tatsumaki might try to use her powers to move Saitama as a joke, but it doesn't work. This creates a humorous moment and also shows their relationship. Also, show how Saitama's lack of fear affects Tatsumaki. She might be used to people being intimidated by her, but Saitama is different. This can lead to her respecting him more and changing her attitude towards him. Their character dynamics should be a mix of comedy, action, and a bit of romance if the fanfic is going in that direction.
In a romantic setting, their relationship might start off slowly. Saitama would probably be oblivious to Tatsumaki's initial feelings. Tatsumaki, being the proud and strong - willed character she is, would have a hard time expressing her emotions directly. It could start with small acts of kindness from Tatsumaki towards Saitama, like using her powers to fix his apartment when it gets destroyed in a fight. Saitama might just think it's a normal thing at first.
One popular aspect in One Punch Man subterranean fanfiction is the re - imagining of the subterranean races. Writers often give them more complex backstories and motives. For example, some fanfics might depict a subterranean character who has a change of heart and decides to side with the surface - dwellers. This adds an interesting layer of depth to the story as it challenges the traditional view of the subterranean as simply enemies in the original work.