Don't Panic, I Have a Sign-In System

In the world of charlatans, humans are no longer the masters, but the lambs raised by the charlatans. After the efforts of countless sages, mankind finally found a way to fight against the evil spirits. The object of the charm can have extraordinary power after contracting, and can kill the charm. This kind of person is called a killer. Yunsheng, who traveled through time, was marked by a bloody trick at the beginning and fell into great danger. Fortunately, he successfully activated the sign-in system...