Kingdom Hearts Dark Road

Xehanort, living bored on the Destiny Islands, is approached by Ansem, his Heartless from the future, and is shuffled through a portal to Scala Ad Caelum, a world where Keyblade Wielders are trained. Some time later, Xehanort, now a Keyblade Wielder, and his classmates Eraqus, Urd, Bragi, Vor, and Hermod are told by their master Odin that seven upperclassmen have gone missing before their Mark of Mastery exam, with the sister of fellow classmate Baldr among them. While they are far from ready, Odin tasks the youths to find the missing seven by scouring the many worlds.

Before they leave, Xehanort and his classmates discuss the state of the worlds: even long after the events of the Keyblade War, many fragments of the World are still forming, and those that have already formed flow on different timeframes — while one may be far in the future in terms of technology, another may be still in the beginnings of bearing life or basic technological advancements. With that in mind, and the order not to interfere in the affairs of other worlds, Xehanort and his friends begin their search, splitting into two teams. While they do not find traces of their friends at the end of the day, they remain resolute.

Four years later, Xehanort, having just put fresh flowers on four gravestones, says his goodbyes to Eraqus, stating he's going off on his own, to see what the master hasn't shown them. While Eraqus hates the idea, he isn't going to stop him, knowing that he'll be back since they need to settle the score for their games.