What should I read if I where looking for a concept/back story/hermetic effect/minor flaw for a mythic blooded magus descending from the first race of the ancient golden age.
The sundered eagle is very sparse on it, though it names it as a good candidate for mythic blood on page 8.
There's really not that much ON it, since it comes from Greek Mythology and a lot of those sources are lost. The thing in Sundered Eagle is almost a direct quote from Hesiod's "Works and Days".
I'd look at the wikipedia entry on Golden Age and start from there.