The Doom Lord's Spiritual Pet as a Companion

The blood moon is in the sky, the apocalypse is coming, the earth has become a wasteland, science and technology are developing rapidly, beast masters are born, and Luo Xiaoyao, whose soul has traveled through the wasteland, accidentally obtains the system and becomes the master of the land. What kind of glorious story will "he" with the system write in this wasteland where ferocious beasts are rampant and heroes are competing for the throne?