Felicia's mind was set on not being a monster so much that she didn't turn back into her naga form when Requiem left.  It was too painful in her mind remembering who she was before and what she'd done since the incident.  Timidly, she looked up to Kaori and Dante, fear in her eyes as she trembled...her own mind becoming a place of torture for her that she just wanted to forget it all and start all over again...a life without her knowing of her killing, a life without the pain she felt in her heart, a life without this constant suffering.