Well, 'blackmail' is a bad practice where someone forces another through threats. 'Degradation' has a negative connotation of making someone or something seem less worthy. But a'sex story' along with these is not something we should encourage or discuss in detail as it goes against moral and ethical norms.
Blackmail is a form of coercion. 'Degradation' in this context could mean something that humiliates or demeans a person. But stories that combine these with sexual elements are not acceptable in a civilized society. We should promote positive, ethical and legal content instead.