10 Best Times Supervillains Switched Sides

6. Joker - Dark Nights Metal

Given just how sick, twisted and demented the Joker is it was always going to take a lot for Batman to contemplate an alliance. Fortunately for readers this 'a lot' occurred in 2018's Dark Nights Metal, a comic written by the formidable creative duo of Scott Snyder and Greg Capullo, who'd previously marshalled the Dark Knight during the New 52.

For the uninitiated, Metal is pretty much a love-letter to the concept of DC's multiverse. Multiple universes had long been a staple of the publisher's superhero comics, dating all the way back to the Silver Age, but Snyder and Capullo added a whole new wrinkle with the idea of the 'Dark Multiverse', a series of realities hidden beneath the map of known DC continuity.

This mythos hides the worst versions of DC's characters, but Batman in particular suffers the most. The reality spawns multiple horrifying versions of Batman, each with their own tragic backstory and powers, but the most horrifying is the Batman Who Laughs, a version of the character corrupted by Joker determined to bring the universe under his boot.

The main problem for Batman, here, is that he's literally fighting himself. He knows every move he can make before he does, and the only way to retaliate is to introduce a little anarchy: the Joker himself.