One interesting storyline could be that Goku, being the ever - eager fighter, challenges Saitama not knowing the true extent of his power. Saitama, on the other hand, is just looking for a normal grocery shopping day. The clash of their personalities, Goku's excitement and Saitama's nonchalance, could lead to a very comical start. Then as the fight progresses, they both start to respect each other's power in different ways.
One interesting plot point is the clash of power systems. Goku's ki - based attacks and transformations like Super Saiyan contrast sharply with Saitama's pure physical strength. For example, in some fanfictions, when they first meet, there's a sense of mutual curiosity about each other's power sources.
Another storyline could be that Thanos, aware of One Punch Man's power, tries to use the Infinity Stones to either eliminate him or make him an ally. There could be a long - drawn - out battle where One Punch Man has to constantly dodge Thanos' attacks while trying to find a way to land his one punch. In the end, he manages to do it and saves the day.
In a one - on - one fight between One Punch Man (Saitama) and Goku, it's really tough to say. Saitama is known for being able to defeat any opponent with just one punch. However, Goku has a vast array of powerful forms and techniques. If Saitama landed his first punch, he'd win instantly. But Goku's speed and ability to constantly power up could potentially give him an edge. He could keep dodging Saitama's punches until he found a way to overpower him. It really depends on how the fight is set up in the fanfiction.
There could be a storyline where Issei challenges Goku to a friendly sparring match to test his own limits. As they fight, they exchange techniques and learn from each other. This could lead to Issei unlocking new forms of his own power, inspired by Goku's Super Saiyan forms. And Goku could also gain new insights into combat from Issei's more unorthodox fighting style.
One possible storyline could be Deku somehow getting Saitama's power in the One Punch Man universe. He might struggle at first to control such overwhelming strength, like accidentally destroying things around him. Another could be a team - up between Deku and Saitama to fight a common enemy that is too powerful for either of them alone. For example, a villain who can absorb powers and is immune to most attacks.
Well, one common storyline could be about Saitama getting involved in various comical and heart - warming relationships within the harem. For example, different female characters might try to understand his overpowered yet simple - minded nature. Maybe a character like Tatsumaki could initially be frustrated by Saitama's nonchalance but gradually develop feelings. Another could be that Genos gets caught in the middle of all the harem chaos as he tries to protect Saitama from any potential harm caused by the female characters' over - enthusiastic advances.
One possible creative storyline could be that Boros somehow manages to survive Saitama's punch and teams up with him. Maybe Boros realizes there are threats in the universe even greater than Saitama and they have to work together. Another storyline could be a time - travel aspect where Boros goes back in time and tries to prevent his own downfall, but in doing so, changes the entire One Punch Man universe. A third creative idea is that Boros' remains are used by a mad scientist in the One Punch Man world to create a new, even more powerful being that has a mix of Boros' powers and some new, unexpected abilities.
One of the interesting storylines is Saitama's journey to become a hero just for fun. He trained so hard that he became extremely powerful, able to defeat any enemy with just one punch. This simple yet comical concept forms the basis of many great adventures as he deals with various monsters and other heroes in the Hero Association.
One interesting scenario could be that Saitama and Tornado team up against a super powerful villain that neither could defeat alone. Their different powers - Saitama's overwhelming strength and Tornado's psychic abilities - would make for an exciting combination.
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.