Was an aside thought a long while ago, to explain that Zodiark's sacrifices weren't 100% as bad as they sounded (not saying it's not 'awesome, plz eat me Zodi'), but the special zone could be inside of Zodiark.

I started the idea from Mushishi but I also become a bit more confident of it's possibility when I learned that Yoshida said he likes Mushishi, one of the Mushi, which was quite cool, is the reason when the main character has his special eye (and is missing one). The darkness Mushi slowly turns these living things to darkness and then they seem to vanish, but through some events Gingko gets to see that they are living in a new beautiful sort of state (one great giant blinding light fish creature).

Sooo anyways back when some people were talking about clear evil and good I had made an attempt to suggest that Zodiark maybe wasn't sacrificing things as much as he was internally purifying. He had them pass through and into him like a giant water filter, extracting what was causing the issues (like preventing people from allowing their creation magic going wild). So naturally Zodiark would be taking some free will (both if you're outside, as he's like "immma fix you whether you like it or not" and inside as he has removed some issues). It neatly explains why he seemed to have an unending thirst for sacrifice, because he was simply doing his function- purify everything and bring order to the world.

Further reference, being that we've Anima and so we've may have some inspiration from FFX - which would be inside Sin. Then we've a number of hints with Zodiark being on the moon and we've the whole FF4 stuff with going to the moon and the decent potential of going within the moon (FFIX as well), the twist then being you're going inside Zodiark.

We may end up needing Zodiark to help us or for the purpose of some merging of the two primals to return from all the chaos. Maybe Zodiark represents order and Hydaelen free will, there are times when we sacrifice will for order (like wearing masks) and there are times we sacrifice order for free will (although those freedoms are constantly under attack by whoever is in power lol). Endwalker representing trying to walk the path of order and chaos (free will).

Anyway, my basic answer is still 'inside da moon' but I want to add a ticket to 'inside Zodiark and or Hydaelen'.