Originally Posted by
Wolfandre
There is truth in this, but someone also brought up the Tribune articles regarding the Avatars: the layman doesn't know about the Celestials/Terrestrials. The only ones that do (researches at the Rhinostery and the Champions of Abyssea) were likely wiped out. So we can assume that these Avatars ARE the Celestials, but they find themselves with differing names based upon survivors' accounts.
I mean, look at notorious monsters in general. They didn't name themselves. Adventurers, travellers, and lesser monsters named them that because of what they do, their accomplishments, or what they are. Otherwise, they'd just be the same monsters, but with tougher stats.