The Imperial in question who chose Clara is one hailed all around the world as a fighter and a hero healer. She fought inside the places of the demons and earned a lot of status and power for herself. But what the world doesn't know is the other side of this demon that yearns for another level of power and status.
The Imperial, that woman, was hailed as one of the very few out there who could heal the soul. But what people didn't know is that she can't just heal the soul, she can use the openings in the cracks of the souls to keep their original memories and everything set. However, she could erase their original set ego to make the people her slaves.
Even I was taken aback by the sheer brilliance in which this demon woman functioned. She, under the guise, hailed as among the heroes of the demons, yet within the darkness, she would make the powerful ones that came to her for help, ones with cracked or hairline problems in their souls, into her servants.