Major spoilers below for anyone who hasn't yet watched The Flash's Season 7 finale!
Season 7 of The Flash came to an end following a two-part finale, and it was full of surprises. Not only did the episode include Barry and Iris’ future kids, with the return of Jessica Parker Kennedy's Nora and the introduction of Jordan Fisher as Bart, but it also included the return of Carlos Valdes' Cisco Ramone, as well as the Flash’s long-time enemy, Eobard Thawne, with Tom Cavanagh back in Reverse-Flash mode.
After having officially exited the series in a full-time capacity, Tom Cavanagh did indeed return to The Flash for the Season 7 finale, but not just as another thorn in Barry's side. In order to get help to defeat the many Godspeeds that were terrorizing Central City, Barry teamed up with his kids, Iris (who got help from the Speed Force), John Wesley Shipp's Jay Garrick, Michelle Harrison's Speed Force Nora, and yes, Eobard Thawne himself.
Instead of trying to help defeat The Flash, Barry’s greatest enemy returned to provide assistance with Godspeed and August, and while Nora and Bart didn’t understand why their father asked for Reverse-Flash’s help rather than theirs, Barry was more than understanding. Since Thawne's ideal future is such where HE'S the one who gets to defeat Barry, it was only normal for him to help with the Godspeed sitch so that he can go back to scheming and trying to eliminate The Flash once and for all on his own terms. Plus, this way, Nora and Bart were out of harm’s immediate path.
After Tom Cavanagh’s exit, it was hard to tell exactly when he would show up in later episodes, as well(s) as whether it would be as a different Wells or as Thawne himself. It’s been implied before that Thawne could return but as someone else without Cavanagh involved, so I was pleasantly surprised to see the actor back in fine form as Thawne/Reverse Flash in the season finale. The fact that it reversed expectations was a great touch as well, not to mention it being the icing on the "returning character" cake, with all those other actors reprising their roles.
In an interview with Entertainment Weekly, The Flash showrunner Eric Wallace discussed the Season 7 finale and everything that went into it. Below, Wallace addressed how long he’d been planning Thawne’s return, which Tom Cavanagh was totally in on, and why he brought the villain back during the Godspeed war.
I've had that idea for a year. It's just been in my pocket and I haven't been able to say a word, and I've been dying to tell everybody. [Laughs.] Like, ‘Just be patient. He's always going to be back.’ Because it was very important when we were establishing a new villain speedster in Godspeed to show how really dangerous Godspeed is. He's so dangerous that the Flash has to partner with his worst enemy to defeat this guy. I told Karan, he flipped. I told Tom way early. Tom's been hiding this for nine months, it's really hilarious. Good for him for keeping the secret.
Eobard Thawne’s return was not expected - at least outside of general theories that he could return at any given moment - and the finale only makes me wonder whether or not Reverse-Flash's role in this series could shift moving forward. Perhaps this could be the beginning of Thawne turning good? Or at least some version of that. Though it's unlikely, given his mega-villainous nature, Tom Cavanagh’s roles in this show are ever-changing, so if there's ever going to be a different version of Thawne in the future, I'd imagine that would be the ideal way to make it happen.
While Season 7 is now in the books, The Flash fans can already look forward to Season 8 arriving on The CW on Tuesday, November 16.