Interstellar Rag King: There's Something Wrong with the Style of My Mecha

Traveling to the interstellar era where mechas were everywhere, Lu Buyi found himself the richest pauper in the universe. The [Civilization Fire] system he was bound to had a knowledge base filled with black technology that could subvert the times, but it issued a series of incredible tasks to him: [Novice mission: pick up ten tons of space junk. Mission reward: Mecha core energy technology (basic version)] When the Federation and the Empire were fighting over a piece of rare metal, Lu Buyi was using discarded cans and engine blades to create a mecha with a unique style. The empire's ace pilot piloted a 100-meter-tall legendary mecha, with the energy muzzle pointed at him: "Indigenous people, suffer death!" Lu Buyi's mecha silently stretched out a rusty wrench and smashed the incoming energy beam with a "ding" sound. "Warning," the system pop-up window appeared, "there is a 0.001% Error in the opponent's mecha's energy core process. It is recommended to use a wrench to hit the third joint of its left leg to correct it." Lu Buyi sighed and looked at the dumbfounded ace across from him: "Um... Your mecha seems to have some quality problems. Do you want to help repair it? Can you give me a discount?"