Zoom was one of the most intriguing aspects of The Flash Season 2, a vicious and maniacal villain to rival even Season 1's awesome Reverse Flash. The final revelations about his identity were perfectly timed to hit us right in the feels, and his mission to conquer the multiverse was the perfect grand design for the heroes to foil in the finale (although to be honest, that could have been drawn out a bit more).
A huge hit with fans, Zoom will definitely go down as one of the best villains ever to feature on The Flash. But he's not done yet.
At the last second, Barry was spared killing Zoom by the Time Wraiths, who swooped in and carried Zoom back to their dimension. It's highly likely that this isn't the last we've seen of this version of Zoom. But there's also Barry's Flashpoint reset to take into account, which has very concerning consequences for the events of Season 2...
Zoom Still At Large
In the last scenes of the finale, Barry traveled back in time to the moment his mother was murdered, saving her from the Reverse Flash. This has the effect of reseting all the events of Season 1 and 2, meaning that the time Barry returns to at the start of Season 3 will be very, very different.
But of course, Barry wasn't just changing the events of his Earth's history, but Earth-2's as well. All the events of Season 2 affected Earth-2, as Zoom journeyed to Earth-1 with the original intent of stealing Flash's speed. Barry and the gang eventually foiled his plans, and everything was well, until Barry's reset.
Now, it's entirely possible that Earth-2 was affected by this timeline shift. This means that Earth-2 is still in the grips of Zoom's reign of terror, and the real Jay Garrick is still trapped in Zoom's lair.
So what's does this mean for The Flash Season 3? Well, it all depends on whether the breaches are created again somehow. If they are, and the characters discover Earth-2 again, it's possible that Zoom will decide to conquer Earth-1. This would seem very repetitive, but suffice to say that the Zoom we know and hate could be back for Season 3. And then of course there's the other Zoom to contend with...
The Black Racer
As the Time Wraiths captured Zoom, they seemed to transform him into a creature who appeared very similar to them. This could well be the Black Racer, the physical manifestation of Death from the DC comics.
The Black Racer is interesting because he's not totally a villain. He's first introduced as one of the New Gods during Darkseid's reign of terror, but as the manifestation of Death the Black Racer is somewhat neutral. After the Flashpoint paradox in the Darkseid War arc, he and Flash merge to become one entity, making Barry one of the New Gods and granting him more superpowers.
The implications for The Flash Season 3 are vast, as the writers can adapt this character however they want. They could turn him into a villain, and this could make for a very interesting plotline as Zoom/the Black Racer tries to escape the clutches of the Time Wraiths. He'll have a lot of terrifying new powers too, which is exciting.
As for the Flashpoint paradox, it's safe to assume that this version of Zoom stands apart from Barry's changes to the timeline — if Legends of Tomorrow proved nothing else, it's that characters' physical presence in the timestream can protect them from timeline alterations. Usually.
Essentially, this means Barry could encounter two versions of Zoom in Season 3: The post-Flashpoint Zoom from Earth-2, and the Black Racer. Which is terrifying, and awesome.