Am I the only person thinking that the Void Ark is just another facility associated with Azys Lla, merely the one associated with research into Voidsent?
Very glad to hear the details about Mhach, but, I'm sticking with my awkward little headcanon about the War of the Magi. I propose that the antagonists each praised one of the Warring Triad above the other: the Amdapori and their White Magic revering Goddess, the Mhachi and their Black Magic revering Demon, and the Nymians with their Arcane Magic revering Fiend. The Amdapori prayed so hard to Goddess at the end of the conflict that her spirit possessed the Flagship (much like we're seeing now with Alexander), and the three cities had parts of them ripped right out of the ground. Nym is largely composed of floating bits of masonry with corrupted crystals by this point, and Amdapor Township is sited in the trunk of a massive tree.
Before the revelation that Mhach was in the Yafaem Saltmoor, I supposed that it was like to have been sited in the chasm where the Invisible City is, now; the ruins there hanging out over the drop as though something "calamitous" happened to them.
As an aside, the areas we've seen the Void Ark aren't particular to the Dravanian side; it's been spotted plenty of times on the Abalathian side as well.