One idea could be that Nathan, the pirate, falls in love with a mermaid. He has to overcome the differences between their worlds, like his fear of the deep sea and her distrust of humans. Another could be Nathan falling for a princess on an island he raids, and he then has to choose between his pirate life and love.
A really interesting plot could be Nathan falling in love with a witch. The witch initially uses her magic to manipulate him, but as time passes, real feelings develop. Nathan has to deal with the fact that his crew is superstitious about witches, and he has to protect her from their attacks while also trying to convince her to use her magic for good instead of her usual self - serving ways.
Nathan as the main character, and his love could be an exotic dancer from a far - off land. She was brought to the pirate - infested port against her will. Nathan saves her from a bad situation, and they start to develop feelings. Another important character could be the captain of a rival pirate ship who also has his eyes on the dancer and becomes a major obstacle in Nathan's love story.
There might be a fanfiction where Nathan, as a pirate, is part of a crew that has a strict no - love policy. But he breaks that rule when he meets a mysterious figure on a deserted island. The story could then revolve around how he balances his love and his loyalty to the crew.
Maybe the kidnapped person is actually a long - lost heir to a powerful kingdom, and the pirates plan to ransom them back to that kingdom. As the story progresses, the kidnapped character forms an unexpected bond with one of the pirates and they start to plot their escape together while also dealing with the politics of the ransom situation.
One idea could be that they face unexpected challenges during the pregnancy. Maybe there are health scares for Peyton or financial difficulties that they need to overcome together. Another plot could involve how their friends and family react to the news. Some might be overjoyed while others could be worried or even jealous.
A great plot for Beast Pirates OC fanfiction could be an OC who is a doctor with a mysterious past. The OC joins the Beast Pirates under false pretenses, claiming to be able to create a super - soldier serum using Devil Fruit powers. As they work within the group, they secretly try to find a way to cure the madness that seems to be a part of the Beast Pirates' nature. Along the way, the OC has to deal with the various power - hungry and unpredictable members of the pirates, like Jack and Queen, while also hiding their true intentions.
One idea could be that Jake and his crew discover a new part of Neverland filled with magical creatures that can talk and have their own unique abilities. Another could be a time - traveling adventure where they go back to the days when Captain Hook was a young pirate just starting out. Or perhaps they find a mysterious treasure map that leads them to a place where the rules of Neverland don't apply.
One idea could be a crossover where Naruto's ninja skills are combined with the Kuja Pirates' unique abilities. For example, Naruto could teach some of the pirates his shadow clone jutsu, and in return, the pirates could show him how to use their weaponry more effectively.
Perhaps in the fanfiction, Nathan and Max are in a world where they are part of a special group or have unique powers. Their pregnancy could be a result of some kind of magical or extraordinary event. They then have to deal with not only the pregnancy but also protecting their unborn child from those who might want to use its potential powers.
Another character could be Nathan's captain or a crewmate. The captain might oppose Nathan's love affair, seeing it as a distraction from their pirating duties. His crewmate could be either supportive or envious of Nathan's relationship, which would add some drama to the story.
One idea could be a role - reversal plot. Instead of the usual power struggles between Kaguya and Miyuki, have them switch personalities for a day. It would be hilarious to see Kaguya being overly confident and forward, while Miyuki is shy and hesitant.