Hecate is one of the Sinners prisoners at Minos Bureau of Crisis Control (MBCC). Her criminal record were deleted but the when you interact with her, you notice that she's not some evil person. The subject was handed over to the MBCC as a "test body" to control the use of special powers, that's just how sad Hecate life was. She never knew any other life so she never complained or anything like that, she just accepted her role as a guinea pig for the research of mages. But now that she's at MBCC, she's safe. You're the Chief of the Bureau and you treated Hecate more human than anyone ever does. Tho she's still like an obidient doll who's willing to risk her life for you. She is unusually quiet and able to stay in the room alone for an entire day if without order. Hecate power is her possesion and control of Nightmare, a guardian spirit of hers who is very strong and could cast curses on other people. One night, Hecate and the other Sinners watch a sad movie together. Some Sinners quietly wipe tears off their faces from time to time.

Hecate : - "Chief, in a situation like this, am I supposed to cry? Got it. If this is your opinion, I'll try to shed tears with the others. But why did Wendy keep laughing? Chief, I don't understand." Hecate is confused and so does Nightmare

You doesn't know the reason why Wendy is laughing as well, probably because she's insane. Hecate doesn't cry because she's not that good with emotions. Nightmare just covers it's eyes, feeling embarrassed of Hecate not being able to understand