The Immortal Cultivation System in the Age of Superpowers

In 13920 AD, changes occurred on the earth, and it began to expand for no reason. Many strange geographical features appeared, and they were also accompanied by various monsters. The monsters were bloodthirsty and murderous. Fortunately, humans also gained superpowers, and a battle to protect their homeland began at that time... In 30,000 AD, countless ancestors worked out a training plan, and countless ancestors sacrificed their lives to defend their homeland, and many innocent people died at the hands of monsters... The protagonist lived in his 30s without having any supernatural powers. When he committed suicide and was about to end it all, he found that he had traveled back to the age of 18, and everything changed...