The following contains spoilers for The Flash Season 9, Episode 12, "A New World, Part Three: Changes," which debuted May 17 on The CW.

It would be a tragedy if The Flash didn't bring back important characters for its final season on The CW. While the most anticipated was Stephen Amell's Oliver Queen, perhaps the most important is Rick Cosnett's Eddie Thawne. As far as the characters are concerned, getting Eddie back (and then losing him to supervillainy) is emotionally devastating in the way the Green Arrow's return was triumphant.

Since sacrificing himself in Season 1, Cosnett has brought Eddie back to The Flash ten times, counting the series finale. Usually, it's a flashback or time-travel situation, sometimes he's a cosmic hallucination because, well, The Flash is a comic book show. This is the first time the Eddie Thawne comes back to the show. The one who sacrificed himself to save everyone but ultimately failed in the mission to destroy the Flash's greatest enemy. Hiding the resurrected character in the future serves the larger narrative of the show. Making Eddie break bad also breaks viewers' hearts and gives Rick Cosnett a chance to eat up all the scenery since The Flash doesn't need it anymore. It's yet another perfect blend of comic book camp and emotional storytelling that will break fans' hearts.

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Eddie Thawne Went From Red-Herring Villain to Fan-Favorite Hero

Rick Cosnett as Eddie thawne looking very worried in the Flash

Eddie's death is still one of the show's most controversial because he sacrificed himself to rid the timeline of Flash's greatest villain. An ancestor to Eobard Thawne, when Eddie died the Reverse Flash should've been erased from the timeline. He wasn't. In "A New World, Part Three: Changes," his arguments make a lot of sense even though he's under the influence of the evil Negative Speed Force. He sacrificed his life to save Barry and Iris in one moment, not Nora and everyone else the Reverse Flash harmed.

Along with being an early red herring for the identity of the Reverse Flash, Eddie Thawne was Barry's romantic rival for Iris. Both Grant Gustin and Candice Patton get to play very different reunion scenes with Cosnett. In both, Eddie seems like the guy fans remember, but by the end of each scene he's full of the rage and manic energy that just screams "Supervillain." Fans are given back a long-lost character for a few moments before he turns on them. This is a smart move because viewers are hoping that Eddie's better angels win out; instead, he becomes the newest Big Bad for the show. Though the series finale trailer suggests every other Big Bad is showing up, too.

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Rick Cosnett Was an Original Member of Team Flash and Deserves His Moment

Joe and Iris West The Flash

Before Barry even brought Iris into Team Flash, Eddie found his way to the group through Jesse L. Martin's Detective Joe West. His contribution to defeating the Reverse Flash was the most monumental (at that moment) and the most selfless. As Tom Cavanaugh continued to appear as Eobard, fans made many of the same arguments Eddie makes in the episode. However, like the apparently permanent death of Caitlin Snow, there is no justice for him. While Barry will do everything he can to save his life, Eddie himself points out that he probably doesn't get to walk away from all this. The storytellers will give Iris and Barry a happy ending, but not every beloved character gets one.

Hopefully, getting to play an over-the-top villain is as fun for Rick Cosnett as it looks. Even when Eddie gets a little mustache-twirly, Cosnett can ground those moments with enough of the character fans know to make it sting. The storytellers may surprise everyone, but at least Cosnett can give ol' Eddie a heart-wrenching death scene.

The series finale of The Flash debuts on The CW, Wednesday, May 24, 2023, at 8 PM EST.