A Frozen Family
Eight-teen years ago, Rapunzel and Jack Frost's daughter, Elsa, was stolen by Pitch Black. Elsa grew up with an ice cold heart. She made ice monsters and created the harshest blizzards. She even helped Pitch with his nightmares. She grew up not knowing her mother and father, and her sister Anna. When Anna had turned 18, Rapunzel told her about her sister. During the dark of the night, when her mother and father were asleep, Anna set off to try to find Elsa, and bring her back home. She meets friends, and obstacles on the way. But will she find Elsa, and manage to convince her to come back?
This is a Rise of the Guardians, Tangled, Frozen Crossover.