Original/Supporting Character can be any fairly well-fleshed out character that is not our main couple, from what I remember. Yvonne's George wasn't the focus of the fic, but had a very large role in the story. Mamba was co-nominated in Tank's To Protect and Serve II, and I don't remember him being a good guy in the fic.

"You need me. You wouldn't be much of a hero without a villain. And you do love being the hero, don't you. The cheering children, the swooning women, you love it so much, it's made you my most reliable accomplice." -- Lex Luthor to Superman, Question Authority, Justice League Unlimited