[5.3 spoilers] Musings...

I haven't gotten through the Trial yet, though I have it unlocked

Just to establish where I am in story in terms of revelations.

But something that just occurred to be about the Exarch...

...his soul is "unusually dense," according to Elidibus, and that's because he's already been through the Rejoining of the Eighth Umbral Calamity before he used the Crystal Tower to yeet himself through the void to the First.

Well, the Rejoining involves the fragment of a soul on one world rejoining with the rest of the soul on the Source

so he's merged with the fragment of his soul that was on the First in his timeline...

...but he's traveled in time as well as in space, so he came out on the First before the Rejoining

So...does this mean that the First's version of him is still wandering around?

the being that "G'raha Tia" would have been had he been born on the First?

It wouldn't even have to be a Mystel, considering that the WoL certainly isn't required to be the same species as Ardbert.

yeah, first graha is presumably out there somewhere