One Piece: I Was Forced to Become the World's Strongest

[System + trading + multiple Devil Fruits] Roy transmigrates to the One Piece world and awakens the Myriad Things Trading System, which lets him trade goods from the Myriad Worlds. He aims to overthrow the Four Emperors, the Marines, and the World Government, and become the strongest. He tricks all sorts of characters from the story to rake in huge profits. “What I sell isn't jars. It's destiny.” Mihawk: “So this is the sword path of killing... This new path is astonishingly powerful...” Enel: “Stop fighting! You can have all my gold. I'll be your underling and help take down those who call themselves ‘gods.’” Blackbeard: “That's right... This is the power I want, the power to overturn the world! I'm done being human!” Luffy: “You can trade anything? I'll give up twenty years of my life for the power to save Ace!” Ace: “This Pure Lotus Demon Flame is too powerful! The Flame-Flame Fruit? Even a dog wouldn't eat it!” Roy stood on the ruins of Marineford and made an announcement to the whole world. “Give up searching for the elusive One Piece!” “The Great Pirate Era has begun! Do you want power, wealth, everything? I've put it all out on the open sea. Set sail for your dreams!”