Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

Honestly you can still do whatever you want with the Emperor's origin. For instance you could take a story of his origin and mix an old one in. Many shamans sacrificed their lives to lead to the birth of the Emperor. They did this not by pouring their power into a vessel but by going on a spirit quest to gather the shards of a broken old one and unified it into a still developing baby. Carrying a bit of an old one's soul burned these shaman out with its power and they died.

pm713 wrote:
Correct me if I'm wrong but the Old Ones went extinct long before humanity started up didn't they?

Actually there is lore that supposedly Slaanesh tracked down the last Old One, shattered it, scattered it throughout the galaxy so it could still bear witness to what happened to the galaxy, and it's fragments became the Umbra. Of course this might not have been the last one because the Tau background. Even if this was completely true though, it would mean the Old Ones were around still when humans came about.

The Old Ones' civilization was destroyed, which is different from they went extinct.

A summary of the bit about Slaanesh can be found here:
http://wh40k.lexicanum.com/wiki/Old_Ones

It apparently comes from Xenology so just look for that in the text.