Prologue

During a visit with another island, the Straw Hats encounter a strange devil fruit user. Upon them attacking, Katsu is transported to another demention.

One where they don't have pirates or devil fruits, where there are different countries run by different governments. Where instead of pirates they have heros, and instead of devil fruits they have quirks.

Everything there is strange, and she just wants to get back to her crew. However, while she is there, she might as well go with the flow right?

She's just a pirate playing hero.