Robie Amell put all speculations and doubts to rest when he guaranteed he would return to "The Flash" as the supervillain Deathstorm in the second half of Season 2. Ever since the death of his character Ronnie in The CW series, fans have been hoping and praying this is one of those comic book deaths where the character gets to return with the help of loopholes; and now, those prayers have come true.
However, this version of Deathstorm, whom we are hoping to see in Earth 2, is going to be very different from what we know from the comic books. In the comic book universe, it was explained that the first Firestorm, aka Ronnie, was brought "back to life" as a member of the Black Lantern Corps during the Blackest Night. After quite a bit of complicated villainy and resurrections, Ronnie was able to get back to his heroic self, but Firestorm then got separated, resulting in the emergence of Deathstorm.
"The Flash" incidentally is not going to get into all these details, but is merely going to use the name Deathstorm to denote an evil version of Ronnie that is living in Earth 2. He will be married to Killer Frost aka Caitlin Snow (Danielle Panabaker) of Earth 2, who is also pretty evil.
In the comic books, Killer Frost is capable of absorbing heat from external sources and transforms them into waves of cold. However, only Firestorm is capable of providing the warmth she needs to survive, and probably that is the story they are going with in Earth 2 of "The Flash".
In a promo for the upcoming Season 2 Episode 10, "Potential Energy", we see her drawling, "It's sooo much more fun to be bad." The badass couple in all probability may be tasked by Zoom to attack the Flash (Grant Gustin), just to get him to be faster.
"The Flash" will return with Season 2 Episode 10 only two weeks later, on Tuesday, 19 January, but ahead of that do not forget to check back here for more updates and spoilers.