I was reading this thread for fun, not really having anything to contribute or anything that I especially needed to learn from it, until I read what Emily wrote:
Quote
In the L&C series, he was vulnerable to hypnosis, which isn't exactly magic, but it's associated with it.
I'm currently writing a fic that involves hypnosis and I can't remember what episode you're referring to. I vaugely remember something about hypnosis now that you mention it, but the only ep I can think of is Oedipus Wrecks and that was Lois, not Clark.

*thinks some more* Okay now I remember that he wa hypnotized in JSN, but were there any other eps?

~Anna