Quote Originally Posted by LineageRazor View Post
She also noted that Zodiark "coveted power"; perhaps he coveted that power as a kind of self-defense, in order to stop the Ancients from harming the planet with their Creation magic. He used the Sound to agitate them, and took advantage of their great Summoning in order to gain an active form.
I believe that this is related to the manner in which Hydaelyn and Zodiark behave in regards of sacrifice. Hydaelyn doesn't seem to encourage worship of herself, nor does she require ritual sacrifice in the form of lives or aether. Instead she rewards a select few champions with her blessing when they perform some manner of sacrifice personal to them, such as the actions taken by Ardbert and company as seen during Shadowbringers' role quests. She also seems to have no compulsion against bleeding herself dry, so to speak, in the defense of her champions, as seen in the Praetorium wherein she shields us from the unleashed Ultima spell.

By contrast, according to Emet-Selch the Ancients had to sacrifice their own lives so that Zodiark would do what was asked of him, be it ending the calamity destroying their world or restoring life to it. it's possible that, like Hydaelyn, Zodiark doesn't actually require this, but rather does it as a sort of equivalent exchange in order to avoid expending his own power. A being who values self-sacrifice as much as Hydaelyn seems to might see that as coveting power.