I'm.. starting to doubt that to be really honest - it would be a little
too convinent for his avatar to be Azem's soul shard, where every other RPR has a random voidsent (yes, I know Yoshi has dropped hints about
being 'special' and having a connection to the story, but again, too convinent in my opinion). If anything, I'm starting to lean more to Azem's 13th soul fragment being the
mysterious 'black knight' introduced in 6.1 who is totally not Golbez - it would make perfect sense, especially how Golbez in FFIV was FFIV protagonist Cecil's brother.
Either way, we'll find out eventually.