I did this with photoshop, here is the story.

legend claims she was mutilated in a car crash. When the Slit-Mouthed Woman has found a victim she will appear before them wearing the surgical mask. She will then ask the person if they think she is beautiful.

If the person responds no she will then kill them. If the person responds yes she will then remove the mask and reveal her deformed face. In order to escape becoming the next victim of the Slit-Mouthed Woman one must attempt to outsmart her.

One way to do it is to answer her in a way in which she is not accustomed to. For example, when she asks her would-be victim if they think she is beautiful the person can respond with, "You are of average looks".

This will confuse her as she is used to either a yes or no answer. Instead of being frightened one can respectfully bid her pardon and advise her that one is late for a prior commitment and cannot stop to speak with her.