After Duan Fei died in his previous life, he was reborn and returned to 20 years ago, a few hours before the virus affliction. Duan Fei's regrets for those 20 years can finally be remedied by using his 20 years of knowledge from his previous life to arm himself in the present world. Duan Fei, who has obtained the evolutionary tree, is constantly improving his strength. Although he was the only survivor in the previous life, Now he is a world hero in this life…