what of hypnotism and subconscious manipulation?

Get someone into a position where their mental defenses are weak, such as hypnosis, light trance or even certain sleep phases, and begin to work on their subconscious. Give them instructions, orders, triggers, whatever. Eventually, the subconscious will reprogram the conscious mind to follow it's orders, your orders. That is probably the easiest way to conceive the idea of Mind Control.