The insinuation about allogenes has been clear since the genshin webcomic!
Venti knows what happens to vision wielders and could only tell us about it in riddles because he's not allowed (the mouth of Barbatos is literally covered in lunar arcanum)
Venti knows it's all empty
When Venti recounts it in the webcomic, using mythological examples of sacrifice, it's framed as if HP is using those who ascended to maintain his world? 🤔