Board Thread:The Flash discussions/@comment-27700324-20180418041345/@comment-24152851-20180419010842

She's certainly her own individual, but how the split personality arose to begin with seems tied to the ice powers. Ultimately a split personality is another side of the same person's mind, one personality may be dormant while the other is active, but they don't have a separate soul/mind to themselves. Really doubt Caitlin's Killer Frost is trapped in a piece of DNA.