I'm Surrounded by Ogres

"Your name is Song Wantang. You are a human being, not a demon." "There are demons around you, don't trust anyone." "The police think you have committed murder. You must prove your innocence." "You need to kill all the demons to be free. There is no other way." "If any two of the above are wrong, please go to Haitang Clinic immediately." Lawyer Song Wantang had just traveled through time when he saw a blood letter written on the ceiling by the original owner or... Rules? There were still doubts until Song Wantang found the body in the refrigerator. The demon in the apartment began to act, and the siren downstairs became clearer and louder, announcing the date of his death...