The "security guard-looking" "person" probably wasn't a nurtured evil spirit, because nobody wants to nurture an evil spirit in their forties or fifties. They'd already seen too much of life and held few extravagant hopes. If there was really a need to nurture one, it would only yield half the result with twice the effort. Their resentment, compared to that of a child who died prematurely, was like heaven and earth.
Then it's possible that the "person" before me could be a walking corpse, but wouldn't a walking corpse taking its head off be tantamount to self-destruction?
"Hehe, little smart head, aren't you thinking hard? Let me tell you, I'm neither human nor ghost," the security guard said, voicing my inner thoughts exactly. It seemed he did have a trick or two up his sleeve.
Huh? He can read my mind? Mind reading should not be possible through a walking corpse; so, could it be that this "person" is the one who cast the Ghost Nurturing Spell?