Lillian is Silas' third familiar although she had been destined to be his familiar for thousands upon thousands of years. Being a Syrath, she is known as a sadist demon. Upon physical touch there is a pain that is so intense it is on a complete new level of pain that a person or being has ever felt at once. Often it causes somebody to faint, yet most of the time they die from the pain. 

 

Lillian was dubbed to be Silas' God Mother soon after his own mother's death and she was given the task of caring for him while he was still Seras although she was sealed within a hammer protecting him. Her physical body immortalized within a large crystal, only way she'd be freed is if they were to break the crystal and replace her soul within her body giving her all of her power that she had stolen when she was sealed.