General info :
Xion (Shion) is the de facto fourteenth member of Organization XIII, introduced in 358/2 Days. First appearing as a featureless, hooded figure, she comes to form her own identity during her time spent working alongside Roxas, bonding over their similarities such as a lack of memories of their past lives and an ability to wield a Keyblade. She eventually comes to forge a strong friendship with Roxas and Axel. After Riku makes her question her own existence, Xion discovers that she is a Replica—an artificial human—designed to absorb Sora's scattered memories following the events of Chain of Memories and duplicate Roxas's powers as a fail-safe for the Organization's plan, and is not counted as an official member of the Organization. Her physical appearance differs among those who see her, with her most prominent form resembling Kairi, who embodies Sora's most precious memories.Because her existence prevents Sora from awakening, Xion is initially torn between staying with her friends and merging with Sora, but she chooses to sacrifice herself when she begins draining Roxas's power. However, she is recaptured and forced to fight Roxas in order to absorb him and become a perfect copy of Sora. After Roxas defeats her, she asks him to release the stolen hearts from Kingdom Hearts before she returns to Sora, erasing all memory of her from those she has encountered. She makes minor appearances in Birth by Sleep, Coded, and Dream Drop Distance, showing her to still exist within Sora's heart.