I did. You missed the point. The "meta" is, you and I have self. If we assume a self exists, then there is one. If we assume there is not, then there is not.
Descartes' Evil Demon by definition, has self in the example. Thus either we both have self, and I can detect the demon, or we do not, and neither can it influence me.
"Don't think of moving a person's arm but compelling the actual person to move that arm"
Assumes movement of an arm is not compelled by thought? If I move my arm, I compel it. If someone else moves it. They did not compel me. The question is, can they compel me with no detection? That is the question, we cannot thus assume in the thought experiment, and if we do, we get erroneous conclusions.
Remove the assumptions you wish to test from the thought experiment. Else it's not a test, it's a set paradox (if use the thought experiment "I *can* go through time and kill my grandfather", I have defined myself as being a paradox, not proven time travel is possible or not ;) I have to ask "*Am I able to* go through time and kill my grandfather" ).
"yet he can alter your thoughts to make you do what he wants, all the while making you think it was our thoughts to begin with." Citation needed, or proof. In that, I can theorise "an undetectable action", but an action is by definition detectable, else it would not be an action! So really, don't get in a twist over the theories, but look to break their mistakes!