One Piece: Building the Strongest Technological Empire from Scratch

【King + technology + the Miao Dao weapon + never sucking up to the protagonist's group + no female lead + no System + Momonosuke and Kozuki Oden must die!】 Luo En, a transmigrated mechanical engineering student, is the founding king of the Four Seasons Kingdom. A year and a half after transmigrating, he obtained two weapons powerful enough to destroy the world. A suit of armor and a starship. He thought he could now kick the Pirate King and punch the Celestial Dragons. But... Luo En discovered that the armor's five metal, wood, water, fire, and earth crystals, along with the starship's nine energy cores, had all been scattered across the world. From then on, Luo En began frantically building up his forces and searching for these 14 gems. When he hadn't found a single one of the 14 gems: “We're good citizens, very, very good citizens.” When he found one: “What? You say I have weapons of mass destruction? All of them?” When he found two: “I don't eat beef.” (He returns to the kingdom in Chapter 7.)