The mid-season final of The Flash season 2 is drawing near, and yet we have no idea who the mysterious speedster from Earth-2 is. All we know is that he is called "Zoom", but as far as his motivation is concerned, there are only possible hints, nothing tangible so far. No surprise there, it was the same in the season 1 with the Reverse Flash. However, in season one it was somewhat obvious that Harrison Wells was the villain, so the writers actually had to work and convince the audience otherwise.
Even though Zoom is shrouded in a veil of mystery, any devoted fan has embraced the challenge of finding out who the speed demon is, before it is revealed in the show. So, if you take into account what we know from the show, and what we know from the comic books, here is the list of suspects that could be the villain in this season of The Flash.
Dr. Edward Clariss - The Rival
Edward Clariss is a scientist who managed to recreate the formula that turned Jay Garrick into a red speedster. Since, his accomplishments weren't adequately acknowledged, Edward became bitter and resorted to a life of villainy. Which means that, if Jay Garrick is The Flash on Earth-2, Edward Clariss is his Reverse Flash, i.e. his rival. However, I believe this is highly unlikely, since it would be unusual to simply throw a new character into the mix at the end of the season when they unmask the villain.
Sure, we saw the real Eobard Thawne when the first season was near its end, but his identity was only used to clarify how he ended up in Harrison's body, it did not have any groundbreaking impact. In other words, Edward is a viable suspect, but the possibility of him being the bad guy who is suddenly introduced to the audience is very low.
Barry Allen
No, not our Barry Allen, Earth-2 Barry Allen, the one we haven't seen yet. Unfortunately, there aren't many clues to support this thesis, other than the fact that Earth-2 is all about what people could end up being under slightly different circumstances. Still that would mean they would have to explain exactly what happened to the other Barry Allen, who wasn't attacked by Reverse Flash as a child, which again makes it unlikely for him to become so sinister.
It would be far more plausible to show the other Barry Allen as a normal man, happy with Iris on Earth-2, making Earth-1 Barry Allen regret ever becoming a superhero (hmmm there will be a lot of Barry Allen(s) in this article apparently). Honestly, the second scenario is far more plausible. Can anyone even imagine Grant Gustin playing a bad guy?
Malcolm Thawne
Malcolm Thawne is another Barry Allen. Well, not really, he is his twin brother. Wait what? Well there is a Flash issue in which Nora Allen gives birth to twins, however at the same time Charlene Thawne loses her baby, because the doctor who needed to deliver it was drunk. And in order to cover his mistake the doctor took one twin and gave it to the Thawne family. Eventually, Malcolm discovers the truth, finds Barry, becomes jealous of the fact that Barry had a better life, and becomes Cobalt Blue, an evil speedster.
Considering how Zoom leaves a trail of blue lighting as he runs, it wouldn't be hard to believe he is Malcolm Thawne. But, then again, Grant Gustin as a villain? Really? This would however, explain what happened to Barry from Earth-2, since he hasn't popped up yet, and it would create a mystery on Earth-1 if there were another Malcolm raised by the Thawne family. It would also explain why he is so hell-bent on killing Flash from Earth-1. On the other hand, it was said that Zoom wants all the speedsters dead, and it was never implied that he has a beef with Barry in particular.
Eobard Thawne
Now we're talking! Eobard Thawne is the most famous villain here, and simply beating him in the first season just doesn't seem like a very good idea. The whole point of the Reverse Flash is that he somehow always catches up to the real Flash - he is simply a problem that cannot be outrun and will continue to persist, no matter what.
So, it can be Eobard Thawne from Earth-2, or from the future again. In the end, who cares. When it comes to explaining these paradoxes everyone has a hard time understanding exactly what is going on. Since we saw the real Eobard Thawne only during the very end of season 1, it would seem logical that we see more of him during season 2. Eobard Thawne and Barry Allen are sworn enemies, so it seems like a very likely scenario.
Henry Allen
Not sure about this one, but it is by far the best theory out there. Henry Allen from Earth-2 was the one who became a speedster after a particle accelerator went kaboom, but the explosion killed his son, which is why he torments Harrison Wells by kidnapping his daughter. Additionally, his speed only reminds him of the tragic event that took place, as well as the existence of any other speedster, so he decided to eradicate them completely.
Furthermore, Zoom's eyes are somewhat similar to Henry's, so this may very well be a viable theory concerning Zoom's identity. Besides, it would be great for two Henrys, who are fundamentally the same person, to turn out to be complete opposites, due to the difference in the lives they've led.
These are the most popular theories regarding Zoom's identity, and the last two would fit the bill perfectly. One thing is certain, it is highly unlikely for us to be disappointed, as this season has been great so far, and it is very likely filled with even more surprises and plot twists, just like the first one. Plus, we are yet to see what the deal is with Hawkgirl and Vandal Savage. Zoom is not the only character who can contribute to an interesting plot development.