After Iris, who had Barry’s powers due to Melting Pot, was in Star Labs with the rest of Team Flash after recapturing Melting Pot. Instead of Switching back Powers, Iris keeps Barry’s Powers and the rest of Team Flash turns their back on Barry. Barry is left with a lot of mixed emotions and his powers disappeared. Meanwhile Caitlin suffer immense headaches, and next day she no longer have killer frost power she was happy to find out but got new ones fire powers. But one day Barry woke up, he feels different. So when he look at the mirror, he was shocked because as his life got weirder now somehow he in the body of....Killler Frost

Note: this isn't a body swap but a Barry’s mind and soul are in killer frost body when Caitlin and frost spilit. Caitlin and Barry now look alike expect Caitlin has Brown hair, Brown eyes, pink lips and Tan skin. Barry has white hair, blue eyes, blue lips, and pale skin.