The "Red Tide Catastrophe" 300 years ago was caused by the impact of red crystal meteorites from outer space. In fact, it was the out-of-control "Star Core Project" of the old civilization - human beings tried to mine alien red crystal energy, triggering dimensional rifts and the influx of red tides (space turbulence containing high concentrations of source matter), causing the world to mutate. Things retreated to the city, species evolved rapidly, and humans retreated to the city.
The protagonist accidentally acquires the products of the old civilization and moves from a slum to the world stage.
