It is clear that Venat does not agree with the convocation's point of view about it's importance over "lesser" beings. On the contrary, Venat does what she can to learn about us as a person, the world we live in and the people in it. She clearly empathises with us as explorers, sundered though we may be and does not automatically dismiss us as some lesser familiar but as a creature in our own right that actually isn't that dissimilar to the ancients themselves. In fact, she has the knowledge that the sundered WoL and friends are much more durable and capable than even an unsundered ancient in Lahabrea, Emet-Selch and Elidibus.

Despite that, Venat doesn't just give up on her own people and immediately sunder the world. She doesn't want to do that, and she pleads with the remaining ancients after Zodiark's summoning to change their ways because she knows if they continue down the path they're on they will fail. She doesn't WANT to believe that the ancients will continue to abuse their immense powers to alleviate their own suffering at the expense of others. She wants them to push through their despair and learn how to live with the inevitable suffering life will throw at them. But they don't.

And if you've ever dealt first hand with despair you'll know all too well that someone telling you "if you keep acting in despair, things will only get worse" doesn't help. Despair and suffering isn't something you can click your fingers and make vanish. But the ancients are powerful enough to cause irreparable damage to themselves and their world before they realise for themselves that they aren't making things better. So yeah, Venat does a terrible thing to them, and forces them to experience suffering without the physical power to fight back and destroy the star itself in the process. Because even though many will still suffer and ultimately fall to despair, it at least means those who do find something to live for and find happiness will not be destroyed.

Venat did tell the ancients of Meteion, which is why she had a small following the help her summon Hydaelyn, but they were vastly outnumbered and weaker in strength than those who did not heed her words and chose to follow Zodiark. Had she not sundered the world, the disciples of Zodiark would surely defeat them and proceed with their self-destruction.

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