Rebirth: Join the Army with a System

Li Tianhua was reborn with the system. In this life, he had to become a frontline fighter. Fighting tomb robbers, drug dealers, and spies. Going abroad to perform missions, being an undercover agent, a doctor, and a scientist. Participating in international special forces competitions to win glory for the motherland. He was called a demon by countless enemies and a smallpox by Western countries, symbolizing the death brought by the smallpox virus. He is a warrior and a hidden guardian of the Great Xia Kingdom! But as he becomes stronger and stronger, he discovers an astonishing secret: this world is not as simple as he thought. ...