Who could be the main antagonist in a 'luffy meets shanks fanfiction'?

The World Government could be the main antagonist. They see both Luffy as a growing threat to their rule as a pirate and Dragon as a revolutionary. When Luffy and Dragon meet, the World Government might send their strongest agents like the Admirals to stop them from joining forces. The World Government's strict control over the world and their desire to maintain the status quo would put them in direct opposition to Luffy and Dragon.

A powerful and corrupt World Noble could be the main antagonist. They might be trying to stop both Luffy and Dragon's efforts for freedom. The World Noble could have a large military force under their control and be causing chaos and oppression in various parts of the world. This would force Luffy and Dragon to join forces to take them down.

One possible plot could be that Luffy, while on a new adventure in a mysterious island, accidentally discovers a hidden treasure map that leads to a place Shanks has been looking for. Luffy decides to find Shanks and share the map. When they meet, they team up to face the various pirates and obstacles in their way to reach the treasure. Along the way, Shanks teaches Luffy some new combat skills and they strengthen their bond as friends and pirates.

In this fanfiction, perhaps Luffy has become much stronger. He might show Shanks his new skills and powers. They could also talk about their adventures since they last met, like Luffy sharing his experiences on different islands.

They could start with a big hug. Then Shanks might tease Luffy about his still - crazy appetite. Luffy, in turn, could show off his new crew members to Shanks.

In fanfiction, when Shanks meets Luffy's crew, it could be a very emotional reunion. Shanks might be impressed by how much Luffy and his crew have grown. He could see the strong bonds within the crew and be proud of Luffy for leading them so well.

In 'Shanks Saves Luffy' fanfiction, Shanks and Luffy are the central figures. However, characters from Shanks' crew could also be involved. They might be there to assist Shanks in the rescue mission or have some sort of back - story related to why Shanks is so determined to save Luffy. Additionally, any new characters created specifically for the fanfiction, perhaps a powerful being who is the root cause of Luffy's danger, could also be main characters in the story.

It could be a new character created specifically for the fanfiction. Maybe a powerful pirate who has a vendetta against the Straw Hat crew because of the oc's presence. Since the oc is reborn into this world, they might bring some sort of change that angers this new antagonist.

It could be a lemon - loving pirate who has a grudge against Luffy for some reason. Maybe Luffy accidentally destroyed his precious lemon grove on an island. So this pirate, with his crew of lemon - themed fighters, constantly tries to sabotage Luffy's adventures and steal his treasures.

A powerful dragon - themed pirate could be the main antagonist. This pirate has a crew of dragon - like creatures and they are causing chaos across the seas. They have a grudge against Luffy for some reason, perhaps because Luffy has unknowingly entered their territory or stolen something valuable from them.