Are Krax playable? I don't remember them being listed in the list of the faction names a while back.
I am 99% sure that every faction will be playable. Or do you mean in the campeighn? That I'm not sure about, but I doubt it: the GC2 campeighn only had one playable faction. This could easily change, however....
hmm, in Darkodinplus's post there is another symbol with which I am not familar. It is on what appears to be a BLACK mana bar. If it were not for the discovery of the gold version of the life symbol I would have assumed that black mana's symbol to be the death symbol. That entire menu looks a bit more 'death magic' than the others.
The symbol in question is most likely the symbol for Death magic. I am now almost 90% convinced that the Black Rune means "Magic" in general".