I think the uhm thing we're missing here is that when they say bearer... in English that comes across as being, "person who held the stone." If we plug-in a synonym for bearer, then read the line it could be something like:

"The crystal's original incumbent."

Since the stones are made of memories as remembered by the Unsundered of the other offices, it would make more sense that way. Basically, those words they speak of are memorable words that our Azem said. That crystal was made from the memories Hades and they shared. Basically, Hades direct quotes our past life in the crystal, and it's a memory Venat has too.

BFFs5life and all that jazz.

Minor Edit: That is to say, all of the crystals were made of memories relating to the Convocation at the time of The First Final Days. Makes sense, yeah?