Saitama is a very powerful hero in the One Punch Man universe. He can defeat any opponent with just one punch. He has a simple appearance and a somewhat laid - back personality.
Well, Saitama All Fiction could potentially refer to a fan - created idea that emphasizes Saitama's ability to be above all the normal rules of the fictional One Punch Man universe. For example, his strength is so overwhelming that it's like he exists in a realm of his own, where the typical limitations of the story don't really apply to him. He can defeat any foe with just one punch, and this 'All Fiction' concept might be an attempt to explain how and why he's so powerful in such a ridiculous way.
Sometimes King is paired with Saitama. King, known for his false reputation of being a super - strong gamer in the original story, could be in interesting interactions with Saitama in the fanfiction's gaming context. Maybe they compete in a gaming tournament within the fanfiction, and Saitama's effortless wins baffle King.
Saitama's origin story is quite interesting. He was an ordinary man who was frustrated with his job - hunting and general lack of success in life. He decided to become a hero just for fun. He started a very intense training regime that included 100 push - ups, 100 sit - ups, 100 squats and a 10 - kilometer run every day. Through this extreme and consistent training, he gradually became so powerful that he could defeat any opponent with a single punch.
A plot where Saitama travels to different dimensions in the One Punch Man universe. He could encounter strange versions of himself or other heroes and villains, leading to humorous and action - packed situations.
Genos could be an unexpected opponent. He might be forced to fight Saitama due to some mind - control or a misunderstanding in the rules of the tournament. It would be really interesting to see how Saitama would handle fighting his own disciple, and how Genos would fare against his master's incredible strength.
Many 'female saitama fanfic' deal with the theme of adaptation. If Saitama is female, she may have to adapt to different expectations from society. There are also fanfics that focus on the theme of breaking stereotypes. A female Saitama can break the traditional image of a hero being male. This can be seen in fanfics where she shows that her gender doesn't limit her strength and abilities at all.
One common theme is the contrast between Saitama's powerful yet simple - minded nature and the complex relationships in the harem. For example, in many stories, his nonchalance about his growing group of admirers is a source of humor and drama.