One interesting scenario could be that Saitama and Tornado team up against a super powerful villain that neither could defeat alone. Their different powers - Saitama's overwhelming strength and Tornado's psychic abilities - would make for an exciting combination.
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.
Saitama's power is his physical strength which is seemingly limitless. Tornado, on the other hand, has psychic powers. If Tornado could somehow manage to immobilize Saitama before he throws a punch, she might have a chance. However, Saitama has shown resistance to various attacks. In most fanfictions though, the outcome often depends on the theme the writer wants to convey. If it's about the power of the underdog, Tornado might win. But if it's about the ultimate power, Saitama is likely to come out on top.
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.
One plot could be Tornado having to team up with a new, unexpected hero to face a powerful villain that even she has trouble with. This would show a different side of her as she has to work with someone she might not initially get along with.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). There are often many creative works there. Also, some forums dedicated to One Punch Man might have links or discussions about Tornado fanfiction.
In this fanfiction scenario of Saitama meeting Tornado, the story could be centered around their different ways of dealing with threats. Tornado is used to using her psychic powers in a more elaborate and showy way. Saitama, on the other hand, just punches. Their meeting could lead to Tornado being curious about Saitama's simple yet extremely effective method. Maybe she would try to get him to teach her his way, but Saitama would be like 'There's nothing to teach, I just punch'. This could lead to some humorous exchanges between them as they interact more.
One Punch Superman Saitama VS Tornado was the 191st chapter.
Chapter 191," Tornado's Counterattack ", tells the story of the battle between Saitama and Tornado. The two met on the street and Saitama was provoked by Tornado and was involved in the battle. In the battle, Tornado displayed her powerful strength. She used a type of Qigong wave called "Tornado" to attack her opponent, forcing Saitama to display even more strength to fight against her. In the end, Saitama defeated Tornado through his relentless efforts, demonstrating his unparalleled strength and tenacious will.
Another storyline could be that Thanos, aware of One Punch Man's power, tries to use the Infinity Stones to either eliminate him or make him an ally. There could be a long - drawn - out battle where One Punch Man has to constantly dodge Thanos' attacks while trying to find a way to land his one punch. In the end, he manages to do it and saves the day.
One interesting storyline could be that Goku, being the ever - eager fighter, challenges Saitama not knowing the true extent of his power. Saitama, on the other hand, is just looking for a normal grocery shopping day. The clash of their personalities, Goku's excitement and Saitama's nonchalance, could lead to a very comical start. Then as the fight progresses, they both start to respect each other's power in different ways.