The 4th snow sister. After frost died catliyn and mark worked on bringing frost back. but in return he " killed" catlyin bringing out Khione, but after sometime the sisters chose to bring catlyin back. Now some time has gone by for the flash but catilyn feels something's off. She hears this voice in her head, same as when she learned about frost. she sometimes loses time and that's when you take over. She believes frost may be back so she tells mark. But your not frost, not Caitlyn not Khione. You're someone else.