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.
For a One Punch Man Monster OC in fanfiction, consider its weaknesses. Even though it's a monster, it can't be all - powerful. Maybe it has a fear of bright lights, so heroes could use that against it. Its personality could be really cocky because of its unique powers, but that could also be its downfall. It might underestimate its opponents and get beaten as a result.
It's likely about King from One Punch Man in a visual novel format. It might focus on his adventures, his relationship with other characters in the One Punch Man universe, and perhaps explore his unique 'pretend' hero status in more detail.
Obviously, King himself is a very popular character in 'One Punch Man King' fanfiction. He is often the center of the story, whether it's about exploring his mysterious powers or his relationships with other heroes. Another popular character is Saitama. Since they are both part of the hero association, there are many fanfictions that involve their interactions, like Saitama being curious about King's supposed feats of strength.
One interesting 'One Punch Man King' fanfiction could be where King actually has some hidden powers that he's been suppressing. In this fanfic, he might start to slowly reveal his true strength during a really tough battle against a new and extremely powerful monster. It could be a story that focuses on his internal struggle between wanting to keep his low - key image and having to step up to protect the city.
An engaging plot could involve the monster OC having a goal that the heroes initially misunderstand. For example, the monster is actually trying to protect a certain area from a greater threat, but the heroes think it's attacking. As the story progresses, the truth is revealed. Along the way, there can be epic battles where the heroes learn more about the monster's powers and weaknesses.
You can find 'One Punch Man' fanfictions on websites like FanFiction.net. It has a large collection of fan - created stories related to 'One Punch Man'. There are different categories and ratings, so you can easily filter and find the ones that suit your taste.
The main character is King. But other characters from the One Punch Man universe may also make appearances, like Saitama who is often associated with King due to the misunderstandings regarding King's 'heroic deeds' which are actually Saitama's most of the time.