Eraqus was worried about a great many things, nearly all of them revolve around his duties as the only active keyblade master in the land of departure.
One worry was his apprentices, Terra, the oldest, was barely a teen, and he had awakened his keyblade, and as expected, it was a physically oriented one named Earthshaker, adding to the boys already growing strength, Eraqus was worried that the boy would let that strength get to his head.
He worried about his younger apprentice, a blue haired girl named Aqua, while she could never even hope to match Terra's pure physical strength, she had magic in excess. He was afraid he would be unable to teach her properly, he was like terra, focused on the physical aspect of the keyblade, and while he was competent with magic, as a master was expected to be, as well as having years of experience, he still did not have the knowledge to teach her magic properly, he had had to ask Merlin and Yin Sid for pointers and advice, but even then, he had to mostly let her figure out the advanced theory herself.
He worried about their relationship, they seemed like good friends, but so had he and Xehanort, he had thought he understood his friend, but as it turned out, he hadn't, why would anyone willingly use darkness for any reason. He had learned later that Yin Sid had always had doubts about the boy, the man had told him that noticing things like that was easier when you were a third party
Finally, he was worried about a world, Yin Sid had recently pointed out that this world's light had dimmed ever so slightly, and had been doing so gradually for a few years, and had only noticed recently, and asked him to make sure the darkness hadn't changed its tactics.
So here he was, traveling through the lanes in between with his two apprentices, this wasn't the first time they have visited other world's with him, but this would be the first where they would be allowed to explore on their own, he trusted them and believed that they were old and responsible enough to do so
"Terra, Aqua, we've arrived."
AN, Kinda short, but it's a prologue, the others will be longer
