Alien Race

Maybe the introduction is not very good, please, the main text must be better than the title and introduction. I really can't write the title of the book. Alien races invaded the earth, and the dark realm spread on the earth. Humanity retreated step by step, and held on for 50 years. During this period, due to the constant pressure from the invasion of alien races, science and technology developed rapidly. Finally, 50 years later, humans have built dots and dots of cities in this damaged world... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.