10 Times The Joker Basically Defeated Himself

In the Emperor Joker storyline, the title villain became a godlike entity after stealing the powers of the fifth-dimensional imp, Mister Mxyzptlk. (Typical day in the world of comics.)

After reshaping the world in his image, the Joker declared himself the emperor of the universe. Using his newfound godhood, he turned Harley Quinn into a constellation, devoured the entire nation of China, and trapped Batman in a time-loop where he was tortured and killed over and over.

With the Dark Knight unavailable, Superman was the only one capable of stopping the almighty clown. Even though the Man of Steel is considered the world's most powerful superhero, his might couldn't compete against the Joker's omnipotence. Growing tired of Supes' antics, the insidious showman announces he intends to use his power to end all of reality for good.

Realising he can't best the deranged jester by force, Superman panders to his ego, telling him that he won't be able to toy with Batman ever again if he unmade the universe. As the Joker became consumed with self-doubt, he was momentarily vulnerable, allowing Superman to defeat him and return him to normal. (Well, normal by the Joker's standards at least.)