The concept of heroes turned villains has been around in fiction since long before Breaking Bad mastered the trope, and nowhere has it appeared more frequently than the pages of DC and Marvel Comics. The list of superheroes who became villains - whether or not they stayed that way - is surprising both for its length and the number of fan-favorites that appear on it. It seems to happen even more frequently than villains turning hero.
The serial nature of comic book storytelling requires endless plot twists, and that’s resulted in most caped crusaders having at least one face-heel turn in their published history. Even those who most exude the values of truth, justice, and the American way - even Earth’s Mightiest Heroes - are prone to going rogue every now and then, if only for variety’s sake.