Elsa

Elsa is the queen of Arendelle introduced in Kingdom Hearts III, and originally taken from the Disney film . She is sisters with the princess Anna.

Kingdom Hearts Union χ
Elsa's power is channelled by the Book of Prophecies to form the Supernova - Elsa and the Anna & Elsa Medals.

Before Kingdom Hearts III
When Elsa was little, she used to remain close to her younger sister Anna, but one day she shuts her off for some reason.

As the years passed, Anna and Elsa barely saw each other until the day of her coronation, making Anna excited as she thought she finally got a chance to speak with her sister again. Unfortunately, at the party, Anna got into an argument with her sister resulting in her unleashing her magic to push her away. This resulted in Elsa running away from Arendelle feeling frightened she might hurt others

Kingdom Hearts III
Upon arriving in Arendelle Sora first notices the sea turning to Ice. When he questions Donald if it was his magic that did it he denies it and investigates further. From there, Sora sees Elsa fleeing across a lake, transforming the water into ice as she runs feeling scared. Curious if something happened to her, Sora, Donald and Goofy go after her to the north mountain and speak with her. When they meet, Elsa hesitantly asks who are they to which the trio introduces themselves. Elsa tells the trio to return back to the village and needs to be left alone. Feeling concerned, Sora questions if that's bad resulting in Elsa unleashing her magic at the trio, much to their shock. Eventually, this attracted the Heartless appearing leading to the trio taking care of them while she seeks cover.

After defeating the heartless Elsa thanks them for protecting them and apologizes for getting upset, unfortunately, a reindeer-looking Heartless prepares to attack the trio only for Elsa to use her magic on the heartless. Sora is impressed by her ice powers, but Elsa reacts in shame, saying all she does is hurt, people. Sora then tells Elsa to return back home before more Heartless show-up but tells him that the north mountain will be her new home so that she wouldn't hurt anyone saying that Arendelle is safer with her staying up here leading her to create an Ice wall barrier to prevent Sora, Donald and Goofy from continuing following her.

Appearance
Elsa is a young woman with blonde hair and blue eyes. When Sora first encounters her, she wears a teal-and-black dress with a magenta cape and a gold tiara on her French braided crown twist bun. Eventually, Elsa switches to a blue dress, wearing her hair in a loose French braid that is swept over her left shoulder.

Origin
Elsa first appeared in the 2013 Disney film Frozen, voiced by Idina Menzel. She is a composite of two characters from Hans Christian Andersen's : Kai, one of the story's protagonists, and the titular Snow Queen herself.

In Frozen, Elsa and Anna were orphaned at a young age when their parents King Agnarr and Queen Iduna died in a seastorm. Elsa was born with the power to control ice, although it is never explained why. Due to her powers, Elsa developed shame and guilt after almost killing Anna in their childhood. Years later, on the day of her coronation as queen, Elsa accidentally reveals her powers and flees Arendelle in fear after being called a witch. While fleeing, Elsa accidentally puts Arendelle in a increasingly dangerous snowstorm. She builds a castle with her powers, creating Olaf in the process. Anna takes it upon herself to locate her sister and find a way to save Arendelle.