While the elusive vigilante has remained a mystery for a large part of the season, executive producer Wendy Mericle says that parts of that are entirely intentional.
When Prometheus was first introduced on the show, fans realized that he wouldn't exactly share much of his comic book origin - a tactic the show has enjoyed applying to its other villains. Mericle cites one particular big bad, last season's Damien Darhk, as a similar case.
"In the past, we've taken characters from the comic books, and Damian Darhk is a good example of somebody who is well known in the comic books. Neal McDonough does not in any way resemble the characters that we saw in the comic books. So we've always sort of built them from the ground up in some ways. By the same token, we weren't going for the Prometheus character that's in the comic books..."
According to Mericle, this allowed the show's writers to use outside inspiration to shape their interpretation of Prometheus, even classic movie villains.
"Part of the fun of that is that you can draw on other sources of inspiration. One of the things we talked a lot about was American Psycho. We talked about, who are the big manipulators? People like Hannibal Lecter and Kevin Spacey's character in The Usual Suspects and also in Seven. We talked a lot about those types of villains and how to bring that element into the series."
As Mericle explained, this inspiration allowed the conflict between him and Team Arrow to be more mental than physical, something that has been seen throughout this season. As the villain explained himself, he would rather emotionally manipulate Oliver into wishing he was dead, than outright kill him himself.
"We were looking for something different to do in Season 5, a way to change it up and make it different. The comic book characters are great, and they usually do end up in sort of a physical duel. We really wanted this to be different and have Prometheus be somebody who is manipulating and torturing Oliver, more psychologically than anything else."
With this in mind, the anticipation is only growing as to how exactly Prometheus' plan will come to fruition in the remainder of this season of Arrow.