On p. 86 of "SlaveCraft," slave begins to talk about the mind fuck: "...Masters may be genuinely picky or simply enjoy the predicamentThey may place us in by criticizing our work and ordering it re-done. Some Masters enjoy the mental stress that the predicament generates in the slave. This is emotional sadism, and some Masters find great pleasure in it. Most of the time this is referred to as a 'mind fuck'..." But I'd like to just slightly diverge a bit here, because the mind fuck is not always at a level of emotional sadism. Sometimes it's just for fun, both the Master's and the slave's, whereas true emotional sadism can be genuinely distressing and indeed, can cause great harm to the slave psyche if the Master is not careful, just as an irresponsible Master can indelibly harm or mark the physical body. This generally can (in my opinion) only work if the slave also is a emotional masochist. That, or the Master must be very, very good at aftercare to keep his slave reassured, and very aware of and attentive to his slave's mental health.
I do know an emotional sadist in real life; indeed, he and his slave wife are good friends of mine. And when he describes some of his more interesting punishments and just things that he does with his slave, I just cringe inside. I know, beyond doubt, that I cannot take emotional sadism... inside I would just shrivel up and die; it would destroy me. I'm not saying that it's wrong, just that it's not for me. But I do also think if you're going to be with a Master who is an emotional sadist, you have to have a very good sense of WHO you are, what your emotional landmines are and what pushes their buttons, and be very clear that this is for you and that you can survive this kind of treatment in a relationship.
Now a good mind fuck... that's just a blast ;)