Note:I just recently completed the Under The Moonlight patch msqs and haven't started Prelude in Violet just yet so please keep spoilers for that hidden or to a minimum
Two things caught my eye while playing.The way Zenos instructed Asahi to turn Yotsuyu into the Primal Tsukiyomi and the Shadow Hunter
Correct me if I'm wrong on this but I'm pretty sure Elidibus is the one possessing Zenos's body and it seems so from the way he talked to Varis
As for the Shadowhunter,that's absolutely Gaius Van Baelsar and I screamed of joy when i saw him and it's clear that he's Gaius from both the Gunblade and the fact he has his mask bundled with all the masks of the Ascians he hunted
My theory that I'm gonna say might not have all the details from Prelude to Violet,but I think we're definitely going to Garlemald in the next expansion of 5.0.Everything seems to be hinting to it from Alphinaud going to Garlemald,all the civil problems inside between the Popularise faction and the Emperor's main forces.We're definitely going to Garlemald to fix that and unfold the scheme that Elidibus and Varis are plotting
God this got me so excited
EDIT:I forgot to mention the Elezen Resistance member with the Katana who had Zenos/Nael's theme playing in his cutscene........did Zenos's soul go to a different body?