Quote Originally Posted by Absimiliard View Post
Because all we have to go on are some murals, a few suppositions, and the word of Emet-Selch himself. The two possibilities we may infer thus far are:

1.) Zodiark had to be resummoned after fulfilling its original task.
2.) Zodiark did not have to be resummoned, but it did not have enough power left after its initial task to restore life and habitability to the ruined landscape.

Nothing we've seen up until this point suggests that he started demanding sacrifices in exchange for the tasks that were given to him.
Ah, in that case, I think we should use the analogy that primals are essentially computer programs. They don't do what they aren't programmed to. And the only way to 'reprogram' Zodiark was to sacrifice some lives to him as a source of energy. He didn't DEMAND it, but it was the only way for the Ancients to get Him to do what they wanted Him to do. In which case, blame the designer and we can all see it boils down to #blameLahabrea.