This question was put on-hold due to apparently being off-topic, probably because someone though the OP was asking "what to write", and it was very unlikely to help anyone else. I don't see neither of these points.
Firstly, despite the wording of his question, he is not asking what to write, rather how to write, as there is a specific character related conundrum he is faced with. His specific problem might not be too relevant to most people (even though mind-control is getting pretty popular nowadays), but the broader problem it is within is relevant to all writers. "How to make your villain menacing?" In this case, there are certain factors making the OP not sure how to tackle the job of making the bad guy menacing.
But just because those factors are specific to his case, doesn't mean the question isn't likely to be helpful to anyone else. Look at the top ranking answer to the question. It is not tackling exactly how the OP should make his exact villain menacing, but rather how to make any villain menacing.
My answer is a bit more specific to his question, which means there are less people that will get help from it, but there's still a considerable amount of people that might find use in it. Because it regards how to make villains that aren't really too present menacing. All in all, I think it was a good question that warranted and resulted in good answers that can be helpful to many. I don't think it is right that it got put on-hold, but then again, I'm not an expert within the rules of this site, so please enlighten me if you disagree.
EDIT: Due to debate with user Cyn, I have come to a slightly different view. In my post I portray the OP's question a lot broader than it actually is. What I really think is that it is still useful, as some of the answers it warrants can teach you how to make any villains menacing. The question itself isn't that broad, but the wisdom to be learnt from seeing the answers to it can help with that broader purpose.