The Posthumous Son of Technology

In a highly AI-enabled future, interstellar shipping lanes are blocked by the "Old God Protocol" - a technological ban left by prehistoric civilizations that prohibits any race from traveling beyond the speed of light. The girl Zero is an illegal clone with the genetic key to crack the agreement embedded in her body. When being hunted by a federal mecha, she accidentally activated the sleeping prehistoric mecha "Ember". She discovered that the "Old Gods" were not an alien race, but a "firewall" left behind after humans evolved to higher dimensions. The price of breaking the ban was to make humans the "technological relics" being hunted in the universe.