Vessel

Sansa is a Vessel. Ever since she was born she has merely been a housing space for demons to move into. When she was a baby, a very powerful demon took refuge in her soul. Since she is young, the demon can only surface when she's unconscious because her soul is still young and strong enough to keep the demon at bay. However if there is something extremely important or life threatening the demon can force its way into Sansa's conscious mind and take over. Rendering Sansa in a temporary stasis in her own body.
When a strange boy enters her school a week before spring break Sansa must come face to face with her past; and her destiny.