Gotham by Gaslight gives us a hint of a Joker figure, in the 'wicked looking jasper' whom Gordon tell Wayne failed to take his own life by drinking strictnine (I *think* that was the drug he used) and wound up with an evil rictus grin. The Jaspar, as I've come to know him, had the potential to be an American Moriarty/Joker amalgam, but now I'm forced to accept the idea that the Bruce Wayne of a hundred years past wouldn't have had the same moral strength his modern counterpart did by giving up the designer drug Venom to increase his crime fighting abilities.
For me, BM:TF ruined all four characters: Batman, the Joker, Two-Face, and Dr. Jeckyll/ Mr. Hyde. It ranks right up there with Castle of the Bat and makes me care nothing for the players involved. All I could muster for them was a little sympathy, and a "Thank GOD it's only an Elseworld!"