The Vengeful Ghost Enters My Dreams

"My name is Sun Wu. When you're attacked by a dream ghost, the first thing you need to do is realize you're dreaming, then figure out its rules for killing. If all goes well, congratulations, you've survived!" A man who called himself a Dream Ghost Master invaded my dreams. But the evil ghost had already killed so many people. By the time I finally realized I was dreaming... it was too late!