Viper here is a Katrion, and has a third eye hidden under her hair. Ever since she got stranded in this dimension, she hid her SOUL and feelings away, turning to murder to fill the emptiness. Soon, she was desperate to feel anything, so she killed even more gruesomely. But as she had hidden her SOUL and feelings, she couldn't feel anything. She just felt.. numb. So now, she's a crazy killing machine, desparetly trying to feel and collect enough SOULs to go home. Yeah.. that's pretty much the backstory.