Since it seems like everyone's posting crazy fan theories, I've decided to throw one out there that I've recently developed that who knows if it will ever even be a possibility. So this also contains spoilers from tonight's episode so just a warning there. Anyways, I was watching another show called Scream Queens that my girl likes, and at the end of the first season it was revealed to be a brother and sister duo that had gone on a murder spree to avenge the death of their parent lost years earlier. For some reason, this reminded me a bit of Arrow. Tonight it was revealed that Prometheus is Adrian Chase. And now it seems like he's working with Susan Williams. Originally I had thought that it was Susan under the mask, but after watching the two shows I began to wonder if maybe Prometheus wasn't the only child of Justin Claybourne, maybe him and Susan are siblings or perhaps even twins. The two have been targeting Oliver this entire season and not it seems like they're working together. It's often been shown that Prometheus is the dark version of Oliver, while Susan has mostly been going up against Thea. Having a dark version of the sibling duo would be an interesting point, and it would be quite the twist if they were revealed to have been working together this whole time (would totally suck for Oliver). Like I said this is my crazy theory that will probably not happen, but would be an interesting twist if it did.