Sub-Star Continent

In 2700, the energy of the Blue and White Star was about to be exhausted, and people launched a spacecraft to find new planets. During the exploration, the spacecraft encountered an accident, and the experimental creatures mutated and crashed into a mysterious continent. The arrival of the alien beasts broke the original peace of the continent. People were enslaved by the powerful alien beasts, and the mainland entered an era of dominance by the alien beasts. In order to make up for mankind's mistakes, astronauts went to the future continent and brought young people with super powers to save people in distress. And the young man has another purpose in going back to the past. Who was it that slaughtered all the people in the Snow Bird Palace?