It just came to my mind; there are a couple of moments in the game where Eraqus and Master Xehanort discuss the keyblade war, and it made me think maybe these two are actually one of the many keyblade weilders who battled in the KBW. It wouldn't be that much of a suprise, as they are both keyblade masters who are both old and well experienced.
If this is something that has already been established and I just forgot about it, my bad.
If this is something that has already been established and I just forgot about it, my bad.