: We are told that all shades were once avatars and as yet,
: in the Myth world we have yet to meet an evil avatar.
This seems to reflect a post-TFL change in the meaning of "Avatara," as well as (possibly) the origin story for Shades. During TFL, all non-Fallen Lord sorcerers were referred to as Avatara, and all of them appear to have been good. Shades were simply Avatara who'd been killed, resurrected and bound to a Fallen Lord.
In Myth2, however, Shades appeared as fully conscious, potentially independent beings who were evil *prior* to their deaths (like Turquine) and had willingly been transformed into undead. Avatara was no longer used to describe all sorcerers; merely those who had dedicated themselves to the Light for a period.
GURPS wrapped it up by defining Avatara as *only* those archmages who were part of the Nine, an organization which had been around since Mazzarin founded it. Shades, now, were simply archmages who had chosen to become undead, and bargained with a more powerful Fallen Lord to accomplish this. They weren't ex-Avatara anymore.
Anyway, I think it's apparent that post-TFL, Myth moved away from the "Dark forces are former Light forces who've been corrupted or killed and resurrected" angle and toward the "Dark forces are always around; they're just more powerful and high-profile during Dark Ages" perspective. Hence the presence of more evil-but-human characters in Soulblighter, like the Baron and Brigands.
--SiliconDream