A lot of fanfictions play with the idea of Boros having some hidden power or strategy that makes the fight more intense and less one - sided than in the original. For example, he might have a power - up that actually challenges Saitama for a while. Another plot could be a time - travel twist where someone goes back in time to change the outcome of the Saitama vs Boros fight, which then has all kinds of consequences for the One Punch Man universe.
First, understand the characters well. Saitama is bored with his power and just wants a good fight, while Boros is a proud and powerful alien seeking a worthy opponent. Then, come up with a unique plot. Don't just rehash their fight from the original. Maybe create a new world or situation for them. For example, a world where all heroes have lost their powers and Saitama and Boros have to work together to save the day. Also, good dialogue is key. Make it sound like how the characters would actually talk. Saitama's simple and straightforward speech and Boros' more grandiose way of speaking.
One possible storyline could be Boros surviving his encounter with Saitama and then seeking redemption. He realizes the vastness of Saitama's power and decides to train under him. This would be an interesting twist as Boros was initially a villain. Another could be a what - if scenario where Saitama and Boros team up to face an even greater threat that arrives on Earth. It would show their dynamic as they work together, with Saitama's nonchalant attitude and Boros' more serious and battle - hungry nature.
Well, some dedicated anime fan communities might also be a good place to look for such fanfiction. For example, Reddit has sub - reddits related to One Punch Man where fans might share or recommend their favorite 'Saitama vs Boros' fanfictions. Also, Tumblr often has fan - created content including fanfiction, so it's worth a search there too.
The only man who could accept Saitama's serious punches and not die was Luo Ren. If you like this type of novel, I recommend you the following: One Punch: Supermarket Selling Man, One Punch: 50/50, One Punch: Superman Revealer. I hope you like my recommendation. Muah ~
One common theme is the exploration of power dynamics. Since Saitama is extremely powerful and Boros was a very strong foe, fanfics often play with how their powers interact. Another theme is redemption. Boros was defeated by Saitama, and some fanfics have him seeking redemption or a new way of life. Friendship is also a theme. Despite their initial fight, they could potentially become friends in some fan - created scenarios.
To write a character - driven story about Saitama, focus on his boredom. Show how his extreme power has made his life lackluster. For example, you could write about his attempts to find a hobby that actually challenges him. Maybe he tries painting, but he's so good at it immediately that he gets bored. This exploration of his search for something to fill the void in his life can be a great character - driven story.
One idea could be Saitama facing an enemy that can copy his strength but not his speed. This would create a unique dynamic as Saitama has to use his wits more than just his punch. Another plot could involve Saitama traveling to a different dimension where his power is nullified and he has to start from scratch to regain his strength. And perhaps a plot where Saitama has to train a new hero who is having trouble controlling their own power, similar to how he was once a regular person trying to become strong.
One possible plot could be that Tornado initially challenges Saitama out of pride. She sees his nonchalant attitude and wants to prove that her psychic powers are superior. Saitama, being Saitama, just goes along with it. As the battle unfolds, Tornado throws everything she has at Saitama, but he just dodges casually. Eventually, Saitama throws a light punch that knocks Tornado back, but not seriously hurt, which makes her realize his true strength.
In a fanfiction scenario between Tornado and Saitama, Saitama would likely win. He's so overpowered that he can defeat any opponent with one punch. Tornado is extremely strong with her psychic powers, but Saitama's strength seems limitless. His simple training routine has made him so powerful that no enemy has been able to withstand his punch so far.