Audrey Burns

Audrey was Mystery's sibling who was his young sister, he still loved her

She has getting so mad at him for murdering her daughter,

He didn't mean to kill her for annoying him.

History
Audrey was born after Viktor's birthday, she was being friendly to him in 13 years, and then she was getting mad to him for nothing.

Audrey was getting extremely mad at her own brother, she doesn't being naughty in 12, especially in 17 age,

If his siblings want to calm her down, Audrey should not get mad.