In regards to something involving the main cast

[Cleretic]

Don't know if it's a thing you go into..but a big irk of mine that you might shed light on is.. why did it have to go down at all like it did? If they could create Meteion, why not create dynamis-based creatures to battle Meteion once the Zodiark shield was up? They could have just unmade Zodiark once all was said and done...

...probably because "reasons".

As mentioned by others, dynamis study just wasn't strong enough to do anything with that. And incidentally, we know from going ourselves that the deck was stacked super hard against them; frankly, even if they were good enough at understanding dynamis to make shock troopers, and good enough at space travel to get them there (which, to be honest, feels like a bigger barrier than we often give credit for), they still would've lost.

As for 'why did it have to go down like it did', well... it kinda didn't? Other options were theoretically available, although even they might not have been any good, but the problem was that the Ancients were ultimately stubborn people who locked themselves into certain approaches. The Convocation didn't have to keep sacrificing to Zodiark, and could've stopped anytime... but they didn't, and kept going down an unsustainable road. Similarly, Venat and her group had other options, and were even trying to pursue some of them, but ultimately the only plan left on the table, for reasons both personal and practical, was the Sundering.

There were other options available to both parties, but that doesn't mean that those other options were inherently better options, or that either side was objectively morally wrong to take the ones they did. Ultimately, they're just... choices made by people. You can love or hate them for those all you want, but no stance is 'correct', even if one or another is the majority in certain circles. It's just up to you to decide where your feelings lie.

Personally, my feelings lie at 'I cannot possibly abide by or dismiss the Ascians' later actions even if I understand the road they took to get to them'.