Well, One Punch Man fanfiction can be really interesting. Some fanfictions might explore the backstories of the characters in more depth. For example, they could expand on Saitama's life before he became so overpowered. It's fascinating to see different interpretations of the characters' personalities and relationships. Some fanfictions might also introduce new villains or scenarios that the original manga or anime didn't cover, which can add a fresh perspective to the One Punch Man universe.
Tornado of Terror would likely be one of the first to try and take on Evil Saitama. She's powerful and confident, but she would soon realize the extent of his power. Mumen Rider, despite being weak, would still stand up to Evil Saitama out of a sense of justice. He would be quickly defeated but his act of courage might inspire other heroes to step up.
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.
I also like the scenes where Saitama is just casually hanging out with the heroes, and they're trying to figure him out. He doesn't fit into their idea of what a hero should be, and the awkward yet hilarious interactions that follow are a great part of these fanfictions. For instance, he might be eating a meal with them, and they're all secretly observing him, wondering how someone so ordinary - looking can be so strong.
The villains would have diverse reactions too. Garou might see the fanfic as a source of inspiration for his own 'evil' plans. He might think that some of the ideas in the fanfic could make him an even more formidable foe. However, if the fanfic makes him look like a complete fool, he'd be enraged. Deep Sea King would be confused by the fanfic, not really understanding the concepts that are different from his simple view of the world. But he might also be intrigued by the new versions of himself presented in the fanfic.
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.
One interesting fanfiction could be where the S class heroes team up in a different way than in the original to face a new super - strong villain. Maybe they have to rely more on strategy rather than just brute strength, which gives a whole new perspective on their characters.
When it comes to a fanfiction about Saitama's training days, it has the potential to be really engaging. We could see the evolution of his training methods, perhaps from simple exercises to more complex and extreme ones. It might also explore his interactions with the people around him during that time, if there were any. For example, did he have any mentors or friends who supported or doubted him? This kind of fanfiction can add a whole new layer to Saitama's character and make us appreciate his journey to becoming One Punch Man even more.