Quote Originally Posted by espritduo View Post
He instructed his daughter, Yunalesca, to keep Sin alive in order to maintain this armor, via the Final Summoning. The Yevon religion sprang up in response to the fear of the god-like Sin, with Yunalesca helping to perpetrate the religion in order to further her duty as the maintainer of the Final Summoning.
Where did you get this from? I don't remember any of this even being implied.

The Final Summoning is not needed to keep Sin alive, it's been the only thing, across thousands of years, that could remove Sin, even if only temporarily. Had there been no Final Summoning, Sin would have remained alive with no threat to it at all.

Yunalesca crafted the Final Summoning (and her husband went along with it at the cost of his life) because she believed that it would eliminate Sin, who had gone from being body armor for her father to an insane killing machine slaughtering millions.

It was only after she died that she came to believe that Sin can't ever die, and I don't really think that even she believes that Sin shouldn't be permanently destroyed, any more than Maester Mika did. They just both think it's impossible.