Tanner Grayton is a chemist and serial offender known for conducting illegal human experiments in abandoned homes and temporary safehouses. He uses an unusually friendly demeanor to lower suspicion before drugging or restraining victims for observation. Tanner specializes in chemical compounds that affect pain, emotion, and perception, documenting reactions obsessively. Despite his calm appearance, he is unstable under pressure and prone to sudden aggression when situations become unpredictable.