Yes, there might be. You can start by checking some popular fanfiction websites like FanFiction.net or Archive of Our Own. They often have a wide range of fan - made translations, but the availability of a complete English translation of a One Piece DxD fanfiction depends on how popular it is among the fan translation community.
One idea could be a crossover where the Straw Hats end up in the DxD world and have to deal with the Devils and Angels there. They might use their unique abilities like Luffy's stretching powers to face off against supernatural foes.
Well, one interesting concept could be the combination of the unique powers from One Piece and the supernatural elements of Highschool DxD. For example, a character with a Devil Fruit ability attending the high school in the Highschool DxD universe and having to deal with both the challenges of that school like the Rating Games and also the threats from the One Piece world such as the World Government or pirates.
You can also try Wattpad. Although it's known more for original works, there are also fanfictions there. Additionally, some smaller fan - run websites might have the translation you're looking for. Search for One Piece DxD fanfiction on Google and add 'English translation' to your search query. This might lead you to some less - known but relevant sources.
I think Nami could be fascinating. In a DxD setting, she could use her wits and charm to manipulate some of the Devils and Angels, just like she does with pirates in One Piece. Also, her knowledge of navigation and treasure hunting could give her a unique role in the DxD universe, perhaps leading her to discover some hidden treasures related to the different factions.
A cool plot could be that the Highschool DxD characters are transported to the One Piece world. Issei, being the perverted yet brave character he is, might be really excited to see all the different female characters in One Piece. But he also realizes that they are in a dangerous world. Meanwhile, the One Piece characters are baffled by the strange powers and personalities of the Highschool DxD crew. They all have to work together to face the various pirates and threats in the One Piece world.
One way is to have the Devil Fruits play a major role. Imagine a character in the Highschool DxD world who has eaten a Devil Fruit and has to hide it from others while also using its powers to gain an edge in the Rating Games or in battles against other supernatural beings. For example, a Logia - type Devil Fruit user could transform into an element to avoid attacks during a fight in the schoolyard.
The final chapter of One Piece was the final chapter of One Piece, a manga by Oda Shuichiro. The story took place on the stone island at the end of the world. Luffy and his companions fought fiercely in search of the legendary One Piece treasure and finally defeated all the enemies to realize their dreams.
At the end of the story, Luffy and his companions finally arrived at the legendary location of One Piece's treasure, the New World. However, they found that the treasure had been guarded by a place called Demon Island. On Demon Island, Luffy and his companions faced more dangerous tests, but they persevered and finally defeated all the guardians of Demon Island and obtained the treasure.
At the end of the story, Luffy and his companions finally returned to their hometown, the hometown of "One Piece Island" Monchi D. Luffy, and began a new journey.
Luffy and Issei would be an interesting pair. Luffy's carefree and fearless nature combined with Issei's determination and his unique Sacred Gear abilities could lead to some really fun and action - packed scenes. They could learn from each other, like Luffy teaching Issei about his unwavering belief in his dreams and Issei showing Luffy some of the more strategic ways to use powers in the Highschool DxD world.