5) Doctor Alchemy
In a first for the show, the other big bad of this season won’t be a speedster but is in fact Doctor Alchemy, a long-running enemy of The Flash in the comics.
Though we got a glimpse at the character in the trailer, we don’t know too much about the show’s interpretation of him. In the source material, Alchemy is really one personality of Multiple Personality Disorder sufferer Albert Desmond. A brilliant chemist, he possesses the Philosopher’s Stone.
We know he will be voiced by Saw’s Tobin Bell, but it is not yet known who is beneath the hood. Our totally unfounded guess is Tom Felton – purely because of the Harry Potter connection.