Humanity's Last Mecha

In AD 3179, human civilization was forced into the last line of defense in the solar system by the "Void Zerg". Genetic evolvers guard the star gates, super technological fleets cruise in deep space, and AI Archons control all resources. Ordinary people can only live in underground cities and survive on rations and oxygen quotas. The protagonist Fang Jin is a maintenance worker at the lowest level of the dungeon. His father left him a rusty mechanical key before he died. Everyone thought it was just scrap metal from the old days. Until the insect wave tore through the moon's defense line and the underground city was about to be cleaned, Fang Jin opened a mecha cemetery deep in the ruins that had been sealed for three hundred years. There sleeps the first generation of human interstellar mecha—— "Fuxi Hao". The system prompts: "It is detected that the driver has no chip, no gene lock, and no mental link." "Primary energy and blood fluctuations detected." "The Guwu Agreement is launched." "Welcome back, human." From then on, an ordinary person who was eliminated by future civilization drove the oldest mecha from the old era, killing across the stars and redefining the direction of human evolution.