Killing the heart, yes, just like the new version of snow-white, these people when they can’t beat someone in his or her goodness they corrupt him/her. It is not easy for one person to do, but a sincere single person can do that, sincere and filthy!
Say suppose if you want to corrupt a really good-natured person you hire a monster, who is downright shameless and corrupt and then pay her to harass him, her in unspeakable ways without being directly involved in any confrontation from her side. She will not get involved into confrontations, she will only provoke the other person to do that. All you do is to ensure that they are stuck together. No matter how hard the victim tries s/he can’t get away from that fiend.
Of course initially s/he will ignore, next s/he will try to avoid but when they won’t work and s/he will have to face that filth day after day sooner or later that person will lose his/her beauty and the crook will win.
He will be able to mock and jeer that he always knew that. His victim on the other hand will become as unpopular, despised as him, maybe more.