Alt-history in general seems to lack that kind of character. We get great men and losers but not enough eccentricity (either short or well past the line into insanity).
Which is odd, really, when one considers how inbred most of the royal families of Europe historically were. In my own TL, I consider Henri III to be lucky that he got off with nothing worse than being blind in one eye.
I must admit mad monarchs are an interest of mine.
Charles II of Spain had really bad luck in that regard - yes, the three generations of uncle-niece progeny had a hand in it, but it wasn't as if the Trastamaras were not inbred.