…have some clause in his contracts that stipulates that, when he guest stars on a fantasy TV show, he has to be A) an exceptionally long-lived character and/or B) one that explicitly tells our protagonists that vampires are bullshit?
In Smallville’s Thirst, he played Milton Fine/Brainiac, who fulfilled the B role.
In Supernatural’s Shut Up, Dr. Phil, he played Don Stark, a witch with a greatly extended lifespan.
In Warehouse 13’s The Living and the Dead, he played Professor Sutton/the Count of St. Germain, a 500-year-old charlatan who, he emphasized, was not a vampire. A + B!
I must say, though, that it’s always a pleasure to see him guest star, especially when he plays a charming rogue, which he does with relish [mmmmmm, relish!] and playfulness.
Also he is hot.