Yes, there are likely some out there. Fanfiction often explores unique crossovers like this. You can check fanfiction websites such as Archive of Our Own or FanFiction.net to find them.
One interesting Trafalgar Law OC fanfiction could be one where the OC is a doctor on his ship, adding a new dynamic to the medical team. They might have a unique backstory that ties into Law's past in some way.
One great Trafalgar Law time travel fanfiction is 'Law's Time - Bound Voyage'. It has an interesting plot where Law travels back in time and tries to change certain events in the One Piece universe. The story is well - written and the author does a great job of staying true to Law's character.
It could be really strange yet interesting. Maybe Naruto would have Law's powers and his calm, calculating demeanor. He might use Law's Room ability in the Naruto universe during battles.
One of the reasons is the potential for character development. In the original One Piece story, Law and Nami don't have a lot of in - depth interactions. Fanfiction gives the opportunity to develop their relationship and characters further. For instance, writers can explore how Law's past traumas might be healed by Nami's positive and determined nature. And Nami, who is often seen as independent, could learn to rely on someone like Law. Also, the 'forbidden love' aspect can be appealing. They come from different crews and have different goals initially, but love can make them bridge those gaps, which makes for some really engaging fanfiction stories.
A crossover with 'Bleach' could be really cool. Law could end up in the Soul Society and his powers would be a mystery to the Shinigami. His ability to create 'Rooms' and manipulate objects within them could be seen as a threat or a new form of spiritual power. He might also get involved in the battles between the Soul Reapers and the Hollows, bringing his own brand of justice and strategy.
Well, there's a fanfiction where Trafalgar Law and Nami get stranded on a mysterious island. In this story, they have to rely on each other to survive. Nami's knowledge of the weather and navigation, and Law's medical skills come in handy. It shows a slow - burning relationship as they learn more about each other's pasts and dreams while trying to find a way off the island. There are also some shorter, more comical fanfictions where Law is flustered by Nami's charm and sassiness.
First, decide which universe you want to cross Law with. Then, think about how Law would fit into that world. For example, if it's a 'Harry Potter' crossover, consider how his powers would interact with magic. Next, come up with a basic plot. It could be something like Law is on a mission in the wizarding world to find a powerful magical artifact. Then start writing an engaging opening, like Law suddenly appearing in Diagon Alley and causing a stir.
One common theme is rivalry - turned - friendship. Since they are both pirates in One Piece, their initial relationship as rivals can develop into something more friendly or even romantic in fanfiction. Another theme is adventure. Writers often create new adventures for them to go on together. Team - up is also a popular theme, where they join forces against a common enemy.
Websites like Archive of Our Own (AO3) are great places to start. There are a large number of fanfictions there, and you can use the search function to specifically look for Trafalgar Law OC fanfictions. You can also filter by things like rating and word count to find the ones that suit your taste.