Traveling Through Primitive Society, I Became the Ancestor of the Human Race

[The protagonist is not mentally retarded] [IQ is online] [Does not cultivate immortality] [Light system] High school student Li Jian accidentally traveled through parallel time and space to the primitive society era. The system asked him to lead the human race to develop and grow. Only in this way can he return to the world he originally lived in. From then on, Li Jian embarked on a path to lead the human race to rise. He unified tribes, developed agriculture, created an army, and established a country. First, march eastward to destroy Xiaoli, the old enemy of your country in the previous life, and then march westward, to destroy the beautiful country. In the end, under his leadership, mankind achieved unprecedented unification. But at this time, the system that had disappeared for a long time suddenly appeared again, and Li Jian learned the causes and consequences of his time traveling into this world. How many things are there in the vast universe that we don't know about? The world we see and the life we ​​experience may be nothing more than a game in the eyes of some beings. Li Jian embarks on a journey again, this time just for himself... (For plot purposes, the system will only appear at the beginning and at the end of this article)