One Piece: Shadow of the Dark Night, Shaking the Vast Seas

Three Devil Fruit powers + eternal life + Chinese martial arts + swordsmanship + a vast power base + technological gear Chen Fan, an anime fan, transmigrated into the world of the sea while watching One Piece. He even ended up in the young body of Marshall D. Teach, the story's greatest villain. From that moment on, Teach's destiny began to change. The protagonist, Marshall D. Teach, has these Devil Fruit powers: the Logia Dark-Dark Fruit, the Paramecia Distortion Fruit, and the Zoan Dragon-Dragon Fruit, an otherworldly species in its Starry Sky Behemoth form. Vice Captain Patrick Heidrich: Zoan Mythical Zoan Dragon-Dragon Fruit, Ancient Yin Dragon form. Adolf Siddler, the Chimera Ant King: Zoan Mythical Zoan Human-Human Fruit, Rock Hell Troll form. After Teach overthrows the World Government and establishes the Huaxia Empire, he stands atop a magnificent platform, clad in a black-and-gold imperial robe. He draws the Emperor's Sword and points it toward the heavens and all the worlds of the universe. “I have unified the world of the sea, brought the realm under one rule, and established the Huaxia Empire. I shall defend our world of the sea and protect our state. In the name of the Imperial Sovereign, I hereby swear: As long as I live, I shall defend our land, wage war across all worlds, crush the four barbarians, and secure Huaxia's eternal foundations. And if I die? My soul shall become a dragon, protecting Huaxia so that it may never fall! Let the Heavenly Dao bear witness, and the Great Dao serve as proof! Let all worlds throughout the universe hear this!”