Here is the medicine, Completely ignore or don't reply to his self-moderated posts, and he will have nothing to delete or reply to. I noticed that his posts are always too altered and moved around different boards, a sign that shows that he is seeking attention.
It's kind of difficult to ignore somebody constantly making damaging allegations against you. This has gone as far as digging up his personal details. Nobody cares about the gender of a person on this forum; it's an anonymous forum. People may have their reasons for acting like other genders. I don't think that's a crime here. So I don't know how he's supposed to ignore that. A person like that will continue till they get the attention they're seeking.
I just hope more members will learn to look at the trust of a user before taking them seriously. Because one glance at the trust of that user and you already know he should not be taken seriously.