A plot could involve a mysterious item that has the power to change the world. Shanks and Mihawk both hear about it and end up chasing it. Along the way, they have to deal with various pirates and marines. As they face these challenges together, they start to respect each other more and their relationship evolves into a unique friendship.
One idea could be that they team up to face a new, extremely powerful enemy that threatens the balance of the New World. This enemy could be a former Rocks Pirate member who was in hiding and now has a plan to take over. Shanks and Mihawk, despite their differences, realize they need to combine their skills.
One plot idea could be that they start off as rivals but then have to team up to face a common enemy. During their time together, they gradually come to understand and respect each other on a deeper level, leading to a change in their relationship.
One idea could be that Shanks teaches Luffy a special, secret Haki technique that only they share. This would give Luffy an edge in his future battles and also strengthen their bond.
One idea could be Mihawk getting transported to a different part of the One Piece world where he has to team up with the Straw Hats to face a new and powerful enemy. Maybe a group of ancient sea gods that are awakened and threatening to destroy all pirates. The Straw Hats could initially be wary of Mihawk but soon realize his skills are crucial for their survival.
A plot could revolve around Perona trying to cheer up Mihawk. Since he is often portrayed as a rather stoic and solitary figure. Perona could use her unique personality and ghostly antics to bring some unexpected humor and light into Mihawk's life. For example, she could create ghosts that re - enact funny scenes from Mihawk's past battles, which at first he is annoyed by but then starts to find amusing.
Well, one interesting plot for a Shanks fanfiction could be that Shanks loses his arm in a completely different way than in the original story. Maybe he sacrifices it to save an entire island from a natural disaster rather than from a sea monster to protect Luffy. Then, the island's people, in gratitude, offer him a powerful ancient weapon that was hidden on their land. This weapon attracts the attention of all the big players in the One Piece world, and Shanks has to fend off attacks from various pirate crews and even the World Government. This could lead to a series of epic battles and strategic maneuvers as Shanks tries to keep the weapon out of the wrong hands and also deal with the new - found fame and danger that comes with it.
One idea could be an OC who is a long - lost relative of Shanks. Maybe they were separated when they were young and the OC has been on a journey to find Shanks. Another could be an OC who is a skilled swordsman and challenges Shanks to a duel, which then turns into an unexpected friendship. Or an OC who is a singer in a bar that Shanks often visits and they share stories and adventures through music.
One idea could be Zoro seeking extra training from Mihawk in a secluded place. During this time, they start to understand each other's pasts and the reasons behind their swordsmanship. Another could be a scenario where they have to team up against a common enemy that threatens the world of swordsmen. This would force them to combine their skills and learn to trust one another on a deeper level.
One great story could be 'The Unlikely Bond'. It explores how Shanks and Mihawk, despite their different outlooks, form a deep connection during a shared adventure on an uncharted island. They start to understand each other's values more and their relationship evolves in an interesting way.
In a Mihawk x Boa fanfiction, the plot could revolve around a mission. Let's say the World Government tasks Mihawk with keeping an eye on Boa because they suspect she might be planning something against them. Mihawk, being the stoic character he is, accepts the mission. Boa, on the other hand, quickly realizes she is being watched. At first, she tries to get rid of Mihawk, but he proves to be a difficult adversary. As time passes, they start to understand each other's motives. Boa's reasons for her actions might be related to protecting her island and people, and Mihawk might start to respect her for that. This could lead to a change in their relationship from one of animosity to mutual understanding and maybe even love.
A fan - favorite is 'The Meeting of the Two Legends'. It shows a scenario where Mihawk and Shanks meet in a more private setting. The story is full of great dialogue and a slow - burning relationship development that keeps you hooked.