While everyone is wondering who Prometheus is and main fan suspects are Tommy Merlyn, Quentin Lance, Roy Harper and Billy Malone I seriously doubt anyone of them. So I would like to share a list of possible candidates which fit following criteria:

  • Met Oliver Queen and/or The Hood 5 to 6 years ago somewhere near Season 1, maybe earlier, maybe later but not significantly so.
  • Has at least vague motive.
  • Would have a reason to conceal the identity.

And the candidates are:

  • Malcolm Merlyn - not that it's very likely, but still: why no one is considering the possibility?.. There should be the reason why he's yet to pop up in Season 5. At the very least he could be the mentor of Prometheus.
  • Kyle Reston - a very interesting theory proposed by MADMIKE400. Reston actually fits into criteria nicely: he has a few good reason to hate both Oliver Queen and his alter ego, he was already quite tough to begin with and training could have made him quite a formidable warrior, he fits Prometheus origin of a child of a pair of criminals (moreover, his father was killed), he has a few reasons to conceal the identity (being a criminal known both to underworld and police) and finally he could have been inspired by the arrow Oliver put in him to switch guns for melee weapons and skill.
  • Teddy Reston - less of a possibility, but fits as well.
  • Leonid Kovar - character who is yet to appear on the show but will probably do eventually. May easily blame Oliver for the downfall of his father, Konstantin Kovar.
  • Drakon - remember Constantine Drakon being one of the first people Oliver encountered and killed as The Hood? Always wanted for some relative of his to appear and be a little be closer to source material (despite I liked late Darren Shahlavi as Drakon).