Phi Brain: Raetsel

Raetsel is a main antagonist in the third season of Phi Brain.  She has a rivalry with series protagonist Kaito Daimon over mutual friend Jin.  Both she and Kaito have what seem like contradictory ideas over what kind of person the amnesiac Jin was.  Raetsel can be kind of aloof and has a tenancy to go her own way; not surprisingly she is often compared to a cat. 

Phi Brain: Melancholy

Melancholy is a member of the antagonist group known as the 'Orpheus Order' in the second season of Phi Brain.  Of the five members she is the only one who possesses an authentic Orpheus Ring.  She comes from a wealthy family, she can be egoistical, selfish, and confident, and she claims to be older than she looks.  A lot of her negative personality traits were likely amplified her Orpheus Ring as in season three she was shown to be isolated and lonely, as well as unsure of how to reconnect to her old friends.