Quote Originally Posted by Anonymoose View Post
On the first pass, I thought it was referring to one being added, as well. But the implication is really that one was lost; they bailed on the Convocation during the Final Days for some reason, leaving their number at thirteen. This is explored around the same time as that we and Ardbert are shards of the same sundered soul, which makes one wonder if perhaps we are the fourteenth. (Maybe we made twelve new friends, lol.)
The fact that that shade recognized our soul and saw Aldbert leads me to believe we are the remnant of the 14th. Plus there's the figure Emet saw us become when we were fighting him adds weight to that conclusion.