Kingdom Hearts χ Back Cover

Kingdom Hearts χ Back Cover is a feature-length, computer-animated film that serves as the tenth installment in the Kingdom Hearts series. It is part of Kingdom Hearts HD 2.8 Final Chapter Prologue and acts as a companion piece to Kingdom Hearts χ. The film is non-interactive and rendered with. It utilizes Kingdom Hearts III's Kingdom Shader.

Story
Long ago, in the "age of fairy tales," the World's light is protected by seven individuals who reside in Daybreak Town and wield unique weapons called "Keyblades": The Master of Masters and his six apprentices. A devastating conflict has been foreseen, and the World's end is imminent. In order to heal it, the Master of Masters gives his disciples unique roles and instructs them to form Unions comprised of other Keyblade wielders. Soon afterwards, the Master of Masters vanishes. One apprentice, Foreteller Ira, is left in charge.

One day, Ira discovers a dark Chirithy. This suggests someone has submitted to darkness and a traitor is present. Foreteller Aced is the primary suspect, and it is soon discovered this was not foretold in the Book of Prophecies written by the Master of Masters. Aced convinces Foreteller Gula to form an alliance with him, but Foreteller Invi dissolves this. Suspecting Invi is the traitor, Aced clashes with her, but their battle is stopped by Foreteller Ava and Gula.

It is revealed Gula possesses a Lost Page from the Book of Prophecies. This confirms the presence of a traitor amongst the Foretellers. Gula is struck down by Aced, but Ava saves the former's life. Aced is then accosted by Ira, but the two reconcile. Ira then seeks out Gula in an attempt to see the Lost Page. He is sent away by Ava, who is tending to Gula's wounds. Gula reveals his intention to summon Kingdom Hearts in order to lure the Master of Masters back to Daybreak Town, but Ava dissuades him from doing so.

Realizing conflict between the Unions is inevitable, Ava acts in accordance with her role and gathers Keyblade wielders who must go into hiding instead of fighting. She dubs them the "Dandelions." Meanwhile, in a barren wasteland, Luxu stands with the Master of Masters's Keyblade and a mysterious box that says "X Super" on it. Looking to the sky, Luxu says, "May my heart be my guiding key."