The situation is a loop and the idea of Hydaelyn exists because it's a paradox with no visible start. That's perfectly fine, the issue there is that Zodiark does not have to be fated. If the convocation is properly warned then they don't have to make him. This is the main issue I take with Venat and the idea that we can't change the timeline. The moment it was hinted that she wouldn't catch Emet up to speed on what he forgot because they might need Hermes I wanted to scream at the screen. Zodiark isn't a permanent solution and I don't think many would argue otherwise. He was the best of a bad situation. Which is why the argument has been "If you inform the convocation of the danger completely then they can probably come up with a better solution." What was Venat doing before the final days started? If it wasn't preparing the convocation for what she knew was coming in this time loop, then I blame her for Zodiark and everything after.