Godbert and Julyan Manderville are the two unaccounted for Ascians, Deudalaphon and Halmarut respectively. We've already seen Pashtarot in a brief scene at the end of 2.X, so he's right out.

Deudalaphon was the Patron of Innovation. So lets look at what Godbert does with as minimal spoilers as possible. In 2.X he somehow has the Meteor survivor ring. Also he SOMEHOW comes to gain a seat on the syndicate AND builds the Gold Saucer in barely 5 years following the Battle of Carteneau. In 3.X he builds GiGi a new body. In 4.X he votes against Nanamo because her plan would lead to stagnation amongst those she wants to help. In 6.X he tricks Gerolt into innovating the latter's techniques and improving on his weapons.

Halmarut held sway over botanical and fungalogical creations. Any good chef will tell you that its the spices that make the meal. A true artist can make shrooms come alive with flavour. What is Julyan? A culinarian. That frying pan of hers....excuse me, but NO ONE else has a pan, or even the ability to WILL their weapons to spontaneously grow that massive. Unless say...they knew the powers of creation magics...

And then there's Hildibrand. Nothing about this moron makes a LICK of sense... Unless you consider the fact his parents are awakened Ascian Overlords, and passed their powers on to their son. At which point you realize that if it wasn't for his good natured idiocy, Emet-Selch would have won.

I can 100% see Emet coming to Godbert and Julyan after Dalamud's fall to begin preparation for the 8th rejoining. At which point the two of them look at each other, look around at the aftermath, then go...naaaahhh! Then subsequently yeet Emet all the way back to Garlemald.