The dodo is reproduced as a messenger, the giant-veined dragonfly is used as an early warning aircraft, the saber-toothed tiger is used as a guard, and ancient creatures are used to defeat the apocalyptic mutant beasts.
From a small oasis of purification, a post-apocalyptic city-state with an ecological cycle and self-sufficiency is built step by step, attracting survivors to defect and transform from "refugees" to "city lords".
The predators coveted the protagonist's replica technology, but were destroyed by the protagonist with a replica of the prehistoric biological army; the apocalyptic forces that once looked down on him turned to ask for cooperation.
