In fanfiction, they can be developed through their interactions with other characters. If they meet a character who challenges their beliefs, say about loyalty to Law. This could cause them to question and grow. Also, putting them in situations where they have to make tough decisions like sacrificing their own desires for the good of the crew would show their growth. For instance, if they have to give up a valuable item they found for the safety of the whole Heart Pirates.
A great plot could be a pre - time skip story where Shachi and Penguin are trying to prove themselves to the Heart Pirates. They take on a small but dangerous mission together, facing pirates who have a unique ability. Along the way, they learn more about their own friendship and grow as individuals. They might start out bickering but by the end, they have a stronger bond.
Viola is a strong - willed and perceptive character. The male reader's personality could be developed to complement hers. For example, if he is more of a carefree spirit, his positive attitude could influence Viola to be a bit more relaxed at times. And in turn, Viola's seriousness can make the male reader more responsible. They can also have shared values like a love for justice or protecting the innocent, which would strengthen their bond as they face challenges together in the fanfiction.
Sanji's chivalrous nature can be further explored. For example, when he and Usopp are in a dangerous situation, Sanji could put himself in harm's way to protect Usopp, which shows his loyalty and sense of honor. Usopp, on the other hand, can develop his courage. Maybe he stands up to a powerful enemy to protect Sanji, overcoming his usual cowardice and growing as a character.
Female characters can be developed by giving them unique skills. For example, a female character could be an expert in navigation, which is crucial in the One Piece world. This skill would make her an invaluable part of Law's crew and also give her a sense of purpose and identity within the story.
One way to develop their relationship further is through cultural exchange. Since Chopper is from Drum Island which has its own unique culture and Robin has traveled to many different places, they could exchange knowledge about different cultures. Robin could teach Chopper about the ancient cultures she has studied through Poneglyphs, and Chopper could share about the traditions on Drum Island. This would not only expand their knowledge but also bring them closer together as they learn more about each other's backgrounds.
Goku would probably be very friendly with Luffy. They both love to fight strong opponents and have a sense of adventure. Goku might be a bit confused by some of the wacky things in the One Piece world like the Devil Fruits at first, but he'd quickly adapt. He'd also likely be impressed by the determination of the other characters like Zoro and Sanji.
They could have heart - to - heart conversations. For example, Shanks could share his past adventures and the lessons he learned from them with Luffy. This would help Luffy gain more wisdom and also deepen their connection.
One way to develop the characters in a One Piece game story is by putting them in moral dilemmas. For example, Nami might face a situation where she has to choose between saving a village from a corrupt pirate or getting a valuable map that could lead to the One Piece. This would test her character and also allow her to grow in different ways.
Explore their relationships more. Maybe they have a long - lost family member who is a key figure in the One Piece world. By delving into this family connection, we can see different sides of the supernova character, such as their loyalty, love, and determination.
Their relationship can be developed through shared adventures. For example, when facing a really tough enemy, Luffy's determination to protect Robin and Robin's trust in Luffy's strength can bring them closer. Each time Luffy saves Robin from danger, it deepens her respect and loyalty to him.