In the DC Comics/Dark Horse Comics crossover Joker-Mask, while vandalizing a museum exhibit, the Joker finds and wears The Mask
Having no desires or personality traits that are hidden, the Joker essentially is himself but with near invulnerability, super speed, strength and other abilities. Using the Mask, Joker is actually able to defeat Batman and become unstoppable. He takes over the Gotham television waves and broadcasts 24/7 destruction.
Becoming bored with this, the Joker commandeers a nuclear bomb to destroy Gotham City. Batman confronts Joker/Mask, and his insistence that the Mask isn't funny forces the Joker to emerge and remove The Mask, then realizing that The Mask had been in control of the Joker ever since he put it on.
Its not a bad book, but having the Joker threaten to deploy a nuclear bomb didn't sit well with me. Look, the Joker is clearly an insane maniac, but he has alway killed with some flair and drama. He kills in such a way that people can appreciate his "artform" if you will.
Does a nuclear bomb fit into the Joker's bag of tricks? I think not.