Aeon Strengths: How do they transform into what they are?

[Markus. D]

Yunalesca is only related to aeons being a final trial to those who wish to activate a final aeon.

i think somewhere in FFX it says that: Aeons are Avatars of the fayth, the way these Avatars come to look how they do, is the personality and thoughts of the fayth before it lost its life to Sin... blah blah blah etc......

edit: dont include the blah blah blah etc part.