Well first off, it's not mind control. It's body control. The person is very much aware of what is going on when someone else is controlling them.

[He would know, he has both done it before and had it done to him.]

Secondly, Sfeer Theory isn't about body control alone. In fact, that is merely one small subset of what one can study, and it is one of the most difficult skills to learn. Most people use Sfeer Theory to start fires or to transform raw materials into something else entirely.