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.
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.
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.
Saitama's origin story is quite interesting. He was an ordinary man who was frustrated with his job - hunting and general lack of success in life. He decided to become a hero just for fun. He started a very intense training regime that included 100 push - ups, 100 sit - ups, 100 squats and a 10 - kilometer run every day. Through this extreme and consistent training, he gradually became so powerful that he could defeat any opponent with a single punch.
Saitama is a very powerful hero in the One Punch Man universe. He can defeat any opponent with just one punch. He has a simple appearance and a somewhat laid - back personality.
The villains would have a mixed reaction. Some of the more power - hungry ones might see this as an opportunity to join forces with Saitama and cause even more chaos. However, there would also be villains who are afraid of Saitama's power, even if he's on their side now. They would be worried that he could turn on them at any moment. Overall, Saitama turning evil would completely disrupt the existing power dynamics in the One Punch Man world.
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.
Sometimes King is paired with Saitama. King, known for his false reputation of being a super - strong gamer in the original story, could be in interesting interactions with Saitama in the fanfiction's gaming context. Maybe they compete in a gaming tournament within the fanfiction, and Saitama's effortless wins baffle King.