If Saitama became a monster in fanfiction, his physical appearance would surely change drastically. His bald head, which is now a symbol of his simplicity and power, might take on a more menacing look. His eyes could turn red, and his muscles might bulge in an even more grotesque way. This transformation could also affect his relationships. Genos, for example, would be in a difficult position. He idolizes Saitama as his master, but if Saitama becomes a monster, Genos might have to fight him to protect the city.
Saitama's relationships would be completely upended. Friends like King would no longer be able to approach him casually. And his relationship with the citizens would change from protector to feared being. His new monstrous nature might also attract other villains and monsters, who could either try to follow him or challenge his new - found power.
A cool plot might be a time - travel fanfiction. Saitama travels back in time to when he was just starting to become strong. He meets his past self and tries to guide him, but also has to deal with monsters from that era who are now different threats due to the time shift. And there could be a mystery element where Saitama has to figure out why time is acting strangely in the first place.
One way is to introduce a personal conflict for Saitama. For example, he discovers that his extreme strength has unforeseen consequences for the world or for his relationships. This could lead him on a journey of self - discovery. He might have to make sacrifices or learn to control his power in a new way. This arc would show his growth as a character as he grapples with these new challenges.
Another plot could involve Saitama using his new S - Class status to reform the hero system. He might see all the flaws in it, like how some heroes are more concerned with fame than actually saving people. So, he starts making changes from the inside. He could introduce new training methods or even a new ranking system that focuses more on a hero's selfless deeds rather than just their power level.
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.
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.
One common theme is the exploration of Saitama's power in different universes. For example, when he crosses over to a universe with magic, how his physical strength compares to magical abilities.
The novelty. Since Saitama is originally male, a female version brings a fresh perspective. It allows for new storylines and character interactions. For example, how would a female Saitama interact with the male - dominated hero society in One Punch Man? It also gives room for exploring different power dynamics and emotional responses.
Identity exploration is also a theme. The sister might be struggling with being in Saitama's shadow or trying to find her own identity as a hero or just as an individual. She could be trying to make a name for herself without relying on her brother's fame.
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.