When Leon was on a mission to rescue Ashley, he met a Shinobi agent, she was sent for the same reason. It was dangerous for him, because he developed possession for Leon, she would kill for him, she would do anything. She manipulated Leon without him having any idea, it was as if she put her hands over his eyes, and she didn't allow him to see anything beyond her. When Leon had contact with other people she watched him all the time, from afar.

"But you belong to me." She tells him