Arrow villain Prometheus is set to show up in the upcoming Crisis On Earth-X crossover event. Prometheus-X, as we'll call him, was teased on the poster that announced the roster of the crossover, but now it's official.

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The crossover features a whole host of heroes, who will be battling their villainous counterparts from an alternate earth that saw the Nazis win World War II. What's surprising about Prometheus' villainous return is that Josh Segarra won't be reprising his role as the character, as confirmed by Entertainment Weekly.

In Season 5 of Arrow, it was insinuated by Oliver Queen that Quentin Lance could have been behind the mask, but in the end he was revealed to be Adrian Chase. We know Colton Haynes, known in the Arrowverse as Roy Harper, is returning to Arrow some time soon, so that's another name we can toss into the ring of speculation.

This crossover is set to be bigger, better, and more involved than last year's spectacle. “When we first did the crossover, I guess back in our third season and The Flash’s first season, it was very much like ‘It’s an episode of The Flash where I show up, and then an episode of Arrow where he shows up,'” Stephen Amell said recently. “And even last year, it was like ‘You know, Flash showed up on Supergirl, and then it was an episode of The Flash, an episode of Arrow, and an episode of Legends.’ But this year is just a four-hour movie.”

“I can’t spoil it, other than to say that when I read the crossover scripts this year, I felt compelled to email the sort of original [Arrow] team of Greg Berlanti and Andrew Kreisberg and Marc Guggenheim,” the Arrow actor continued. “And the email just simply said ‘Guys, thank you so much for this opportunity, because it’s going to be really, really good.'”

RELATED: Arrow’s Amell Says Earth-X Crossover Is Like a 4-Hour Movie

Last year’s Arrowverse crossover, “Invasion!,” brought together the stars of Arrow, The Flash, Legends of Tomorrow and Supergirl for a story inspired by the 1988 DC Comics event of the same name.

This year’s four-part crossover will air across two nights, beginning Monday, Nov. 27, with Supergirl and Arrow (on a special night for one week only), and concluding Tuesday, Nov. 28, with The Flash and Legends of Tomorrow.