Dominate Water Margin with the System

Zhao Jun, a modern special forces soldier, unfortunately died while performing a mission, and then traveled through the four years of Zhenghe in the Northern Song Dynasty, and he also learned that this was the world of Water Margin. Fortunately, he successfully activated the system. Not only can he receive a gift package for newbies, but he can also sign in once a month. With this system, there is something wrong with the emperor's brain. (This is my first time writing a novel of this type, so please forgive me for the bad writing and geography!)