A good Saitama Tatsumaki fanfiction often has well - developed characters. It should stay true to the original personalities of Saitama and Tatsumaki from the One Punch Man series. For example, Saitama's nonchalant attitude towards most things and Tatsumaki's prideful and powerful nature. The plot also matters. It could be an interesting new adventure that involves both of them, or a different take on their relationship, like a budding romance that still respects their individual quirks.
The best place to find Saitama Tatsumaki fanfiction is probably Archive of Our Own. It has a great search function that lets you narrow down by tags like 'Saitama', 'Tatsumaki', and other relevant categories such as genre (e.g. romance, adventure) or rating. Another option is to follow some well - known fanfiction writers on social media platforms. They may announce when they release new Saitama Tatsumaki fanfictions or recommend works from other writers.
The theme of the OC being an outsider is also quite common. Tatsumaki is part of a certain world in the original work. So when an OC enters that world, there are always elements of the OC trying to adapt, facing prejudice or suspicion, and ultimately finding their place, often with Tatsumaki's help or against her initial opposition.
One good tatsumaki x oc fanfiction is 'Tatsumaki's New Companion'. It has an interesting plot where the OC has unique powers that complement Tatsumaki's. The interactions between them are well - written, showing a gradual development of their relationship.
Maybe Tatsumaki would be impressed by the power display or decide to interfere to show her own strength. It all depends on how the fanfic writer imagines her reaction and actions.
Tatsumaki's anime and manga commands don't always match. Sometimes, the anime simplifies or modifies them for better animation flow. The manga, on the other hand, might offer more depth and context to the commands.