Ever since Caitlin Snow appeared way back in the very first episode of The Flash, many have been waiting for the moment that she goes down the dark roads of villainy and becomes Killer Frost, her roguish alter-ego in the comic book world. Well, after a brief tease during last seasons final episode, Welcome to Earth-2 saw us finally introduced properly to the evil, chilling, ice-cold Killer Frost. Oh, and her other half, the ominously-named Deathstorm although you may know him better as Ronnie Raymond. Seeing these two over-the-top, scenery-chewing villains fleshed out on screen was awesome to behold, and it was great to see Danielle Panabaker and Robbie Amell given the chance to let loose as a couple of Zooms minions.