I thought it worked. I liked the idea that he was a normal guy and at the end, he just went abit crazy, put on a burlap sack and got tazed like a little bitch.
Then again, I like the whole added realism to all the villains. With Ra\'s, a character this immortal, instead of a Lazarus Pit, it is hinted at that "Ra\'s", is nothing more than a title, that is passed down so that one person takes the spot of another, in a sense of immortality.
Just like with this Joker, we don\'t really get an back story. All we know is that he has scars around his mouth, for a fake smile and he at one point says, " What doesn\'t kill us...makes us.....Stranger.." . He\'s just some nut job who went total ape shit and it works.