Doomsday Hunter System

My name is Yang Yu. I am nineteen years old. I am an ordinary young man. I feel like I am in a dream. A zombie virus suddenly broke out. My parents sacrificed their lives to keep me and my little sister alive... We finally escaped from the zombies, but fell into the hands of the bad guys. They attacked me desperately with electric batons... By mistake, a powerful current opened a system in my mind, and the crisis I faced became more and more serious...