One Piece: That's Not How You Use the Door-Door Fruit

Door-Door Fruit powers, no System, no female lead, multiple Devil Fruits, a man who takes responsibility This is a story about “protection,” and a legend about “destruction.” After transmigrating into the world of pirates, Alex never dreamed of becoming Pirate King. He only wanted to live a peaceful life with his companions. But the world wouldn't let him. If that's how it is, then let the world tremble! In public, he is a rising star in the Navy. Once he leaves the Navy, he becomes an arbiter who strikes fear across the seas. In the shadows, he is the “Black King,” ruling the underworld and secretly commanding a technological empire. He uses the Door-Door Fruit to connect the past and future, and the Qilin Fruit to break through genetic restraints and forge a body fit for gods and demons. With multiple Devil Fruits and armor, he stands invincible in the world. Doflamingo is his pawn, the Four Emperors are his whetstones, and the God's Knights and Imu will all become corpses beneath his feet! “Be content with improving yourself when poor, and help the whole world when prosperous.” When that day comes, Alex stands before the Empty Throne and looks back. Behind him stretches a dawn for countless people. “I never wanted to be a savior. But with this kind of power, I can't exactly do nothing. If the world is dark and chaotic, I'll destroy it all and rebuild it from the ground up.” Looking at his companions, he gently strokes the hair of his sister, returned from the dead. “Dia, look. Your big brother has made this world a kinder place for you.”