I am of a scientific mind so my knowledge on this subject is limited, but is there a way one of the magically-inclined can put a protective spell on the complex against him? If that is even possible. That would seem to be about the only thing we can do, combating magic with magic.
I do apologize for seeming uptight, I just do not like the fact that he can come and go undetected like this. Just for clarification purposes since I do not know him, are we dealing with a future version of himself as opposed to the one that is usually here?