Is Varis actually possessed? At the end of 4.5, Solus/(we presume) Emet-Selch, says he is going to the First:
You shall be the capstone in this world, I the anchor in the shard, and together we shall give the lie to this Star's fraudulent existence.
I know we didn't see Solus in this patch, but Solus is also prominent on the Shadowbringers artwork - in fact the only known antagonist featuring there - and the bulk of the expansion seems to be happening in the First. Can an Ascian be in two bodies at once? Elidibus seems to be sticking with his Zenos meat puppet and his old white robed version is AWOL. I can't remember an occasion where an Ascian occupied multiple bodies, but I'd like to know if I've missed one.
Interesting theory. It is true that only Solus is portrayed as villain, and his position in the artwork is curious from a composition point of view: Minfilia is the central figure of the top, with Solus in the left and Enigma in the right. We know Minfilia is the Word of the Mother, a vessel for Hydaelyn, and Enigma is pretty much tied to the Darkness as he is able to summon souls like the Mothercrystal does and his call is dark-tinged. Perhaps it is meant to symbolize their attitude towards Minfilia: Enigma being an ally, and Solus a threat. Then again, Enigma does want to save the First, and what could be Solus' motives to antagonize the Warrior of Darkness? If Enigma is related to Zodiark, do the Ascians know they are acting against the deity they supposedly serve?
Back to topic, it could be interesting. Assuming Solus is Emet-Selch, he is allegedly one of the most powerful Ascians. Perhaps he is indeed able to travel freely between the First and the Source through a link of sorts by planting a seed or directly possessing Varis, as he mentioned his grandson to be the "capstone in this world".
There is another thing, too. Knowing the Ascians get their names from the Light counterparts of
FFXII's espers, I checked on Emet-Selch's counterpart. It turned out that Emet-Selch, Angel of Truth, is Zalera, the Death Seraph's. This is the Esper of Death, and most importantly, associated with the Zodiac Sign of
Gemini, the Twins.
"Heretic scion who wrapped the world in dark energies, seeking to take the souls of all living things unto himself. Created in opposition to Emet-Selch, Angel of Truth, and scion of light. Originally tasked with the judging of men upon their deaths, his soul was tainted by the curses of those who raged against the heavens, and seizing one of the gods' servants, a shamaness, as a hostage, he rebelled against his creators."
Given my question about Solus' going against his god's will, Zalera's lore implies he rebelled and took a hostage. Mayhap this could apply to Varis, or being a shamaness, another character. Perhaps Minfilia is on his sights.