In the most recent Gamespot review of Update 7 : Destiny Manifest, it is revealed that Villains costume pieces will be available to Heroes where players have access to both games. The /cov command bug was the cause behind many heroes having villains costume parts. Cuppa Jo had made a post containing all the information on it, but essentially since the /cov command bug has been removed from the game, if you do NOT have CoV but you do have a villainous costume piece that you want, do NOT change that costume. To quote the Cuppa Jo:
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For heroes that have a villain costume part OR villains that have a hero part: Those “rogue” costume parts will remain on your character until you visit the tailor again.
When you visit the tailor your rogue costume parts will be replaced with “generic” costume items. You can then change them for a fee to normal costume items OR cancel out and leave your rogue costume items in place. Note – this means that if you want to keep your rogue costume items you cannot change anything on your costume. However – you can change other costumes that do not contain rogue items.
Sorry to be the bearer of bad news to those non-joint holders of the game, but the good news is that if you don';t ever change that outfit, it will never be removed. If you will, please the whole forum post here: