10 Most Powerful Cosmic Entities In DC Comics

5. Mister Mxyzptlk

Superman fans won't need reminding of how much grief the inter-dimensional imp Mister Mxyzptlk has caused the Man of Steel over the years. Mxyzptlk possesses a near unending array of abilities, and while the pre-Crisis version could be bested simply by tricking him into saying his name backwards, subsequent retcons have made the test to banish him back to the fifth dimension slightly more complex.

Mxyzptlk can alter reality on a whim, and it just so happens that Superman tends to be his intended target. For all that Mxyzptlk is powerful though, he only ever uses his abilities for mischief, meaning that their true scale has yet to be determined - at least in his hands.

To get a decent understanding of just how powerful Mxyzptlk is, you have to read Emperor Joker. That particular storyline showcased what would happen if the Clown Prince was ever given Mxysptlk's powers - and it was canon!

The results were also pretty horrifying. Joker used his new godlike potential to create a terrifying new reality where was a God-Emperor. During the Emperor Joker storyline, the Harlequin of Hate also tortured and killed Batman over and over, forcing Superman to steal the Dark Knight's memories so he wouldn't live with the trauma after the whole ordeal was over.