The Flash Season 6 (Part 2): 5 Theories On The Identity Of The New Big Bad

5. Reverse-Flash

As long as he's on the loose, no list of potential Flash Big Bads would be complete without Eobard Thawne, so we may as well jump straight into it by looking at why his return this season is more likely than ever.

The main villain of Season 1, Thawne has recurred throughout the show's run as he's often relied upon to infuse the show with a little bit of that early grit and vitality should it become a little stale. We saw this work wonders last season when he manipulated Nora into helping him escape Death Row at Iron Heights prison in 2049 and gifted an otherwise lacklustre offering with a season finale that would easily rank among the show's best ever episodes. And this breakout resulted in his eventual escape from Team Flash.

In spite of his promise to see Barry at his next Crisis, the Reverse-Flash never returned during Crisis On Infinite Earths for the long-teased showdown that the crossover was supposed to deliver, so without that particular endgame hanging over it, we're all left a little bit confused as to when he'll return. After all, if the purpose of the Season 5 arc wasn't to free him for Crisis, then what was it?

Taking all that into account, it would make relative sense if Thawne were revealed to be the Big Bad of Season 6B (or even Season 7). And, after Nash Wells laid eyes upon an alternate version of Harrison Wells (all of which are supposed to have been wiped out), it's possible that he's already made his return.