Zoro would be deeply affected. He has sworn to follow Luffy and his death would be a huge blow. He might feel like he failed in his duty to protect the captain. He would likely become more withdrawn at first, but then focus on getting stronger to avenge Luffy if there was someone to blame for his death.
Naruto might give Luffy training in stealth. Since Naruto is a ninja, he is well - versed in moving around unnoticed. Luffy, on the other hand, is more of a straightforward fighter. So Naruto could show him how to approach enemies without being detected first, which would be a new and useful skill for Luffy in his pirate adventures.
In a small town, lived brothers Alex and Ben. Ben was ill for a long time. Alex took care of him day and night. But unfortunately, Ben's condition worsened. One morning, Alex found Ben had passed away in his sleep. Alex was heartbroken. He couldn't believe his brother was gone. His world seemed to stop. He started to isolate himself, thinking about all the unfulfilled plans they had together.
Common themes in 'naruto luffy brother fanfiction' include power - sharing. Given their unique abilities, fans like to write about how they would teach each other or combine their powers. Also, friendship is a big theme. Even though they are brothers in these stories, their relationships with other characters from their respective worlds are still important, and the fanfictions often explore how they maintain those friendships while being brothers. And of course, there's the theme of family. The idea of them being brothers brings in a whole new family dynamic that wasn't present in the original stories.
Well, there is some 'naruto luffy brother fanfiction'. Some of them explore how their different powers would interact if they were brothers. For example, Naruto's ninjutsu and Luffy's Devil Fruit abilities could make for some really exciting adventures together. Also, the different worlds they come from, the Hidden Leaf Village and the Grand Line, could be combined in creative ways in these fanfictions.
They could go on an adventure to find a powerful treasure that combines the power of the One Piece and some kind of ninja - related artifact. Maybe they'd have to fight against a new enemy that is a combination of pirates and rogue ninjas. They might travel to new islands where Naruto's ninjutsu would be useful for exploring hidden caves, and Luffy's stretching ability would help them reach high places or cross large gaps.
I recommend "One Piece's Little Brother Save Me". The plot of this book is about the main character being a "vessel" and being hunted down by Lord Eam, the Void Throne. He uses the "Little Brother Save Me System" to become stronger. Although it was slightly different from the original novel, it was still very interesting. I hope you like this fairy's recommendation. Muah ~😗
One possible fanfic could be about Luffy's brother Ace meeting Boa Hancock. Maybe Ace could be on a mission near Amazon Lily and they cross paths. He could be initially curious about her powers and her reputation as a beauty. Another idea is a fanfic where Hancock falls for Luffy's brother because he shows some of the same fearless and kind traits as Luffy, but in a different way. It could explore how their relationship develops in the complex world of One Piece.
One common theme is family. Since they are brothers in this fanfiction concept, it often explores how they build and maintain their family bond. Another theme could be power, as both characters have their own unique powers and how they use or combine them can be a big part of the story.
Yes, there are quite a few. You can start by looking on popular fanfiction websites like Archive of Our Own or FanFiction.net. Just search for the specific tag or title in their search bars, and you'll likely find some interesting stories.