There is one commonality between both the idea of demons in the psychological sense and an entity that is distinct and separate from your mind which one might consider as real: there is a degree of unconsciousness however you look at it. You are not aware or fully aware of the phenomena either way, after all you are not sure what to make of it. The funny thing is there is a tendancy to hang on to "what might bes" rather than just the not knowing.
The matter of mind control, in the sense of any particular view being fused and indistinguishable from the conscious mind that exists independent of these views, comes into question here. That fused state is considered as "knowing," which can just as easily be a self fulfilling prophecy. To see a thing as it is, one would need to distinguish and put aside any such interpretive filters and take in the experience with the clarity of simple awareness. If you really want to, you can do this and see for yourself when it comes to any experience. But the catch is its not the self that would want to identify with a certain way of thinking, that identity comes under threat with this perspective. Of course once you realize its just being stuck in a certain view it is not that big of a deal, but while you are identified and think you ARE that way of thinking, it can be very threatening - more threatening than anything that would fit into that way of thinking.