Lucifer

A woman who has grown to entrap the man she's in a relationship with- pulling a 180 from her previously perfect self and morphing into a demon, ultimately resulting in the detriment of the love he once felt for her. It becomes her nature to tie him down through her highly successful manipulative sensuality, stealing his time from the outside world. Progressively his freedom and freewill diminishes and his social life dwindles, eventually becoming virtually non-existent. His world begins to revolve around only her completely and he becomes withdrawn at the realization that she is all he has left. This is how she uses her greatest power; in masquerading as an angel and offering him the love he can no longer find from any other source. Her most common and reliable tactic for coaxing him out of his shell is whispering "I love you" and devoting 100% of her attention to him, making it impossible for him to resist her temptation and what she has to offer. Her temptation is so great that his response is practically automated, much like a robot or machine she operates at will or a drug she supplies to someone addicted to it. It's only once her angel facade disappears once again that his mental clarity returns and he realizes he's been had, and that it was all instigated by her convincing word of choice. It's then, time after time, that he realizes her whisper is simply 'the Lucifer.'