So a while back, it was mentioned that each race would have a character with their own origin story, and thus was never brought up again. That being said, I thought it was forgotten until the recording for it was brought up...
After sifting through some of the more recent videos, I (and probably a few others) have figured out who the 6th character was. Behold, Fane...
Now you're probably wondering how I know its not a custom character. Let me show you another image for comparison...
Notice how in the later one, the "Listen to Origin Story" button isn't there, because custom characters don't have one. All hail our undead overlord, Fane!
P.S. Also a bit of speculation, considering the distribution of stats on Fane, I suspect both his Civil and Combat talents aren't stat related since +2 Intellegence would be the same as the Lizards talents (Also, I serously doubt +1 constitution BY ITSELF would be a talent considering how awful that would be). I speculate his combat talent can be traced back to DOS1, presumeably a resistance to piercing/poison damage.
I also doubt its +1 Loremaster as Enchanters typically have that by default. I've also heard people speculate that taking on the appearance as other races could be the second talent, I doubt it due to how limited civil talents are on other races (even compared to elves). It is more likely that just wearing a mask would suffice if that were the case. I would have assumed it was the ability to talk to the dead, but that's already a source skill mentioned in one of the updates. Maybe its the ability to intimidate any undead races in conversation, idk. Any speculation is welcome as I have no idea what it could be tbh.