Well, we've also had a nice little evil overlord...

It was parasitic in nature, taking hosts and 'repurposing' them. Not a single host ever complained. Of course, they didn't have any free will, so that's not surprising. The evil overlord, Ranoch, was also known as "The lord of Eat". Yes, the creature ate its way into its hosts in a most messy and painful way. Once changed, there was no discovered means of undoing it. With its stomach in another dimension, there was no limit to its appetite. The only reason such an OP character worked at all was that all the other characters in that RP were equally overpowered, and when everyone's super, no one is.