Mafia 21.

Were the killers blocked or something?

It's quite possible.
*Just in case, I looked suspiciously at Ney and added her to my blacklist.*

Many residents sighed sadly, as they had a good relationship with the deceased.

A hint at Mejer's positive status. Most likely, they killed a townsman, although even the "bad guys" can have positive relationships.

And I think Mejer was playing the role of a girl, and a maniac killed him.

Original, but not without merit. However, I believe that the spirits are still a clue.
*I'm making a list of girls.*
Werewolf, Happy Girl, Ney, Pandora... oh, am I on the list too? Okay, while no one is looking, I'll cross myself out...