On Themis [6.4 SPOILER]

[Yuella]

Also remember that the sundering cutscene is not real time. It's a snippet/summary of major events that happened during the Final Days. Maybe Venat did try harder to convince the people not to sacrifice more lives to Zodiark.

[RyuDragnier]

Also remember that the sundering cutscene is not real time. It's a snippet/summary of major events that happened during the Final Days. Maybe Venat did try harder to convince the people not to sacrifice more lives to Zodiark.

We also don't even know how long she tried to convince them. She could have been trying for years, decades, or centuries before the 2nd sacrifices to repair the planet, and then kept trying until before the 3rd, when she realized there was no point. We have no clue when she finally "broke" and realized she couldn't reason with them. Nor do we know just how much the Convocation were willing to listen at all during that time...or even how Z-Elidibus (Zodiark's Heart) reacted if/when Venat tried to speak with him to come up with another method.