Lucius recognised the look she gave him, it was the one his camp had given him before trying to kill him and forcing him to leave. Why couldn't she see that he was the good guy in all this? That he wanted to accept her true self that even she could not bring herself to do. He wanted to free her of the constraints humans put on themselves when they have no sense of purpose.
"One day you will understand why I do these things for you. Unfortunately, today is not that day" Lucius told her and gestured for her to follow him. Although he was gifted with a scalpel and a pen alike, he had decided to leave the actual scarification to a professional for Evie's sake. The man he had employed was waiting for them in the ritual room and too was a witch that practiced the arts considered to be evil amongst many. It was a case of semantics really.