I was thinking that maybe since the foretellers are that important to the story and more details about them will be unraveled in KHIII, they might be the "Lost Masters". In the E3 trailer Xehanort mentions it in plural and maybe these foretellers and the master of master might be the other darknesses...During BBS the time that Xehanort went "missing" he might have actually been searching for the lost masters...Maybe the masters went to the realm of darkness after the Keyblade Ward and were not actually dead and he went to recruit them...What are your thoughts guys?

Yeah, I remember discussing some time ago about the possibility of the Foretellers joining the Darknesses. Given that we only know 6 of them, and 1 or 2 more at most that have a high possibility of being them (I am thinking about Terranort and Vanitas), we lack 5 slots. 5 Foretellers. Coincidence? Probably yes, but we won't know by now for sure

Yep. It is likely we could see the foretellers in some form as a seeker of darkness. 

Okay, so as far as we know (and correct me if I'm wrong) we know that out of the 13 darknesses we have Xehanort, Xemnas, Ansem SoD, Saïx, and Xigbar. Which does leave the high possibility that at least one of the rest could be a Lost Master. Considering that the rest of the darknesses are characters not yet introduced, it's highly likely.

well yeah,here you have 5 of them...6 are the lost masters and adding the master of masters it makes 7...which leaves to the overall being 12...we know from DDD that xehanort is still missing one since he didn't nort Sora so I guess it adds up

I think it's the Foretellers, but, the Foretellers from an alternate reality or the Datascape.