In some saitama x everyone fanfiction, there could be a storyline where Saitama has to train other heroes. Since he's so powerful, he might be able to teach them new techniques or ways of thinking. This could lead to the growth and development of other characters, like Mumen Rider becoming a more capable hero under Saitama's guidance.
Another possible storyline is a love triangle between a Saitama Highschool student, a character from DxD, and another student from their own school. This would add an element of drama and emotion to the fanfiction, as they navigate their feelings while also dealing with the supernatural elements of the DxD world.
One interesting fanfiction storyline could be that Genos discovers a prophecy that Saitama is going to lose his powers. Genos then goes on a mad quest to find a way to prevent this from happening. He visits all kinds of strange places and consults with various powerful beings. Another could be that there is a competition among heroes to see who can train the best new recruit, and Saitama and Genos enter together. They face off against other hero - trainer pairs in various challenges. Also, a story where Genos creates a virtual reality world for Saitama to experience different kinds of battles that he normally wouldn't encounter in the real world, just for Saitama's amusement.
One possible storyline could be Boros surviving his encounter with Saitama and then seeking redemption. He realizes the vastness of Saitama's power and decides to train under him. This would be an interesting twist as Boros was initially a villain. Another could be a what - if scenario where Saitama and Boros team up to face an even greater threat that arrives on Earth. It would show their dynamic as they work together, with Saitama's nonchalant attitude and Boros' more serious and battle - hungry nature.
Saitama and King can also be a popular pairing. King, despite being seen as a powerful hero, is actually a bit of a coward. Saitama, on the other hand, is extremely powerful but often underestimated. Their interactions can create some really funny and interesting stories, like King trying to pretend he's as strong as Saitama in front of others.
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.
One interesting story could be Saitama leveling up in a virtual gaming world in ways that surprise his in - game opponents. He might use his real - world strength in unique ways within the game's mechanics.
Another great crossover would be with One Piece. Saitama could be on a journey with the Straw Hat Pirates. His super strength would come in handy during battles against the various pirates and marines they face. And his comical personality would contrast well with the wacky and diverse personalities of the Straw Hat crew.
One interesting Saitama OC fanfiction could be about an OC who is a new hero in the City-Z. This OC might have a unique power that complements Saitama's strength in unexpected ways. For example, the OC could have the power of telepathy and helps Saitama communicate with monsters before fighting them, adding a new dimension to the battles.
One interesting 'naruto saitama fanfiction' could be about Naruto and Saitama teaming up to fight a powerful villain from both their universes. They would combine Naruto's ninja skills and Saitama's incredible strength.
There are various storylines, like their battles against powerful villains and their bond growing stronger over time.