Originally Posted by
Roogle ^ I thought that the Dark Aeons were summoned by Guado Summoners to stop your party at various points of the game. This sidequest is not available in the North American version of the game. Can someone confirm this for us?
It's not in NTSC/NTSC-J, but I don't believe that the Dark Aeons are supposed to be considered canonical pieces in the mythological workings of Spira, at least, not until FFX-2. If they were, then one might plausibly treat them as summoner-specific versions of an Aeon employed by the religious groups. I looked up the Dark Yojimbo one, but it doesn't appear that the summoner is Guado, he just seems to be a regular summoner-esque person.