So people have been discussing how one of the members of the Convocation of Fourteen left the group over the Zodiark plan. I'm just wondering if there were more details about that member than I remember, since people are speculating that they went on to help summon Hydaelyn or even their soul went onto become us.

I kinda rushed through the endgame a little since I was so hyped to reach the end, and I'm just wondering if I missed a detail or not. The only thing I remember exactly is that Hythlodaeus mentions the Convocation went to Thirteen from Fourteen. Am I missing something, or are people just inferring from that?

(Not that I'm disagreeing with the theories, just wondering if I missed optional text or something.)