An Oath to Return

"An Oath to Return" is the secret ending of Kingdom Hearts III Re Mind. Unlike previous secret endings in the series, there are two possible endings, with one being the "true ending", while the other is a "bad ending". The condition to unlock either ending depends on the outcome of Sora's battle with Yozora in the Secret Episode of Kingdom Hearts III Re Mind.

True Ending
If Sora wins, Yozora stumbles backwards and begins to fade away into light. He muses that his powers aren't needed yet, but when Sora is confused, Yozora simply tells him not to mind before fading away. A light then shines, engulfing all of Shibuya and sending Sora back into the Final World.

Yozora wakes up in a car to his driver, who calls him "commander". The driver asks him if "it" is impressive, to which Yozora looks outside the passenger window and reflects silently. Sora and Yozora both wonder if it was a dream or not. Sora then states that none of this makes any sense to him.

An Oath to Return

KINGDOM HEARTS

Bad Ending
If Yozora wins, Sora stumbles backwards in shock. Yozora apologizes before telling Sora that he doesn't lose. Sora begins to crystalize, with Yozora vowing to save him. A bright line engulfs Shibuya and transports Yozora into the Final World staring at the sky.

Yozora wakes up in a car and muses wistfully. Sora and Yozora both wonder if it was a dream or not. Yozora then states that none of this makes any sense to him.

Characters in order of appearance

 * Yozora's driver can be heard waking him up in the "True Ending".

Unlock criteria
The conditions to unlock the video "An Oath to Return", the player must finish the Limit Cut Episode of Kingdom Hearts III Re Mind before being able to access the Secret Episode, where the player will be able to fight Yozora.

Trivia

 * When Yozora wakes up in the "True Ending", it is a scene-by-scene recreation of the opening to the  2011 trailer. Kingdom Hearts series creator Tetsuya Nomura was originally the head director for Final Fantasy Versus XIII.
 * After Sora is defeated in the "Bad Ending", he crystallizes then promptly blooms into crystal shards before vanishing. The effect is evocative of the "Crystal Stasis" phenomenon from the  compilation, of which Final Fantasy Versus XIII was initially set to be a part of.