The world is not a simple time travel, but a time and space disaster. The real world and a certain post-apocalyptic wasteland future collide and overlap for unknown reasons. What the protagonist and all mankind "travel" to is a superposition wasteland where these two worlds are forcibly merged and the physical rules are chaotic.
Humans not only have to face mutated monsters and lack of resources, but also have to adapt to the occasional flashes of phantoms of the old city, unstable gravity areas, and enemies from "another timeline." What the protagonist carries is the battle memory from his future self. This is both a golden finger and a cause-and-effect paradox that may lead to greater disasters.
