The Flash: 10 Best Villains (so Far)
2. Zoom
Zoom swept into the show's second season like a hurricane, leaving a whole lot of wreckage in his wake. Aside from introducing Earth-1 to a number of Earth-2 villains and nearly destroying the Multiverse, Zoom roundly broke The Flash's body and paraded it around the city, manipulated and traumatized Caitlin Snow, and, of course, broke Barry's spirit by killing his father in the same spot Eobard Thawne killed his mother.
All season long, the truth about Zoom was shrouded in mystery, complicated even after he was revealed to be the "Jay Garrick" the team and audience had come to know thanks to the existence of the man in the iron mask, the introduction of time remnants, and the revelation he was really Hunter Zolomon all along.
As a result, fans were left to speculate about the truth right up until the end of the season, when everything came together about his story, the real Jay Garrick was introduced, and all of it turned out to be the origin story for the Black Flash.