Relics contains miscellaneous bits of info relevant to the Myth story.
This includes canon or pseudo-canon sources of Myth story data beyond the games themselves,
real-world facts and literature which appear to have inspired facets of the Myth world, and
assorted details of Myth's development history.
Tales From Myth:TFL
The official Bungie-authored, Bungie-sanctioned comic which shipped with the Myth II
Handbook and some copies of Myth II - now in PDF!
Chimera
Bungie's free Myth II expansion. Not much impact on the Myth story as we know it, but
it's official material and has a few tidbits like Changelings.
GURPS Myth
A roleplaying sourcebook authorized and approved by Bungie, containing heaps of Myth
story info, albeit of controversial authenticity.