Warning: Spoilers for The Flash season 8, episode 20
The promise of a shocking cameo in Comments from Cecile Horton actress Danielle Nicolet teased the arrival of a returning character whose identity fans had yet to guess. After the finale, it seems that the mystery character in question was none other than Neal McDonough’s Damien Darhk.
Following his role as Arrow season 4’s main villain, the immortal rival of Ra’s al Ghul has evolved into a major recurring Arrowverse character with most of his appearances being on Legends of Tomorrow. Through an alternate future created by the machinations of Tom Cavanagh’s Eobard Cavanagh, the Arrowverse found a way for him to work on The Flash as well. Damien ed The Flash for a two-episode arc as one of the “Armageddon” event’s many crossover characters. And thanks to the Time Stone he gave Joe West (Jesse L. Martin), the show was able to bring him back once more. The Time Stone and the talk he gave Iris West (Candice Patton) were what made it possible for her character to be fully restored in The Flash season 8, episode 20, titled “Negative, Part Two”.
While it’s true that there wasn’t an expectation for Damien Darhk to be the one who would ultimately save Iris, his inclusion is still hardly the surprise it was hyped up to be. Nicolet claimed that The Flash season 8 finale’s cameo would have the fans “screaming” with excitement. According to the actress, this person would be someone who wasn’t “anybody that you’re thinking it might be”. The real problem with this description of Damien Darhk’s role in “Negative, Part Two” is the fact that he was already in season 8. If The Flash hadn’t already used him (particularly in the same season), his appearance in the finale might have garnered a stronger reaction.
The Flash season 8 finale couldn’t have delivered a cameo of such huge proportions by bringing back a character that had already been used just a few months ago in "Armageddon". The tease that was offered implied it would be someone from an earlier season or perhaps a crossover character who hasn’t shown up yet. The hype created hopes for fan favorites like Wally West, Superman, and even Green Arrow. Plus, there was never any big secret that McDonough wasn’t done with his role as Damien Darhk on The Flash. The actor has confirmed in interviews that he would be returning in a future episode.
In light of his “Armageddon” role and the fact that his Time Stone subtly set up a potential return, Damien Darhk just didn’t fit the criteria established by the cameo tease, unfortunately. If there was a major surprise in the episode, it wasn’t Darhk’s cameo. Arguably the most welcome twist in The Flash season 8 finale was the post-credits scene, which set up the arrival of DC Comics villain Cobalt Blue.