In-game description for Ozma:
Caption for the image of the pyramid in the Weeping City of Mhach on page 196, EE3:Originally created by the mages of Mhach as means of protecting their home from what they believed was an unavoidable uprising of voidsent, the magicked spheroid was eventually employed during the War of the Magi to devour the cities of their enemies and send them into a state of dimensional compression.
Proto Ozma doesn't appear to have an in-game description...Two nightmarish beings were said to guard the Nullstone at its apex: Ozma, an enigmatic sphere of terrible power, and Calofisteri, a mighty sorceress who achieved a twisted form of eternal life by imbibing the blood of voidsent.
Demi-Ozma flavor text:
Ozma and Proto Ozma don't have Triple Triad cards, so that's not a source of information either.Call into battle Demi-Ozma─the round mound of spellbound.
After concluding that Ozma of the Weeping City was but a preliminary attempt to weave an aether-based simulacrum of the Eurekan phenomenon Proto Ozma, the Students of Baldesion endeavored to apply similar magicks in the creation of what they dubbed “Demi-Ozma,” hoping to learn what makes the entity tick.
So... based on what's here, Mhach created Ozma as a weapon to COUNTER voidsent, presumably before Mhach started to weaponize voidsent as their preferred tools in the War of the Magi. And the Nullstone, as a contingency against the rebellion of said tools, was guarded by Ozma (a construct meant to trap voidsent) and Calofisteri (a sorceress who ritualistically consumed voidsent blood to become immortal). So while Ozma was originally AND ultimately an anti-voidsent construct, it was apparently deployed to "devour the cities of [Mhach's] enemies and send them into a state of dimensional compression" at some point in Mhach's campaign.
Meanwhile, what we're told in Eureka is that the primal Eureka created Proto Ozma, in addition to the other Eurekan weapons held in the Baldesion Arsenal, which were gathered by Galuf and his students in order to contain the threat of them. Which gives the implication that Proto Ozma is just another Eurekan weapon (albeit a pretty powerful one), and the Mhachi Ozma is a copy of it, (and Demi-Ozma is a neutered version created BY THE STUDENTS to figure out how Ozma works). This, in turn, tells us that while Galuf and the Students turned the Isle of Val into a prison for the primal Eureka, they still had to go out and collect Shin-Zantetsuken, Orlasrach & Munderg, the Lance of Virtue, and Proto Ozma from SOMEWHERE ELSE before bringing them all back to be contained with Eureka on Val.
The detail that Ozma ate cities certainly comports with all of the Fifth Astral Era architecture we're seeing in the South Horn. If it turns out the Occult Crescent has some kind of backdoor into Ozma's compressed dimension, that might explain why it's trapped so many folks who stumble into the place.
Given what we learn about Eureka during Eureka Orthos (that it was utilized and not necessarily created by the Allagans, who used it to create weapons like Zantetsuken and Excalibur) and what we can infer about how the Mhachi learned so much about voidsent in the first place (that they might have stumbled upon an Allagan repository that covered Xande's deal with the Cloud of Darkness and thus got a jumpstart into summoning voidsent for fun and profit), it seems reasonable to assume that the Allagans might have been the ones who had Proto Ozma in the first place.
Which, in turn, leads me to think that Mhach must have encountered Proto Ozma at some point in order to be able to copy it in the first place.
So, the theory I'm getting at here is this:
- During the 5AE, Mhach discovers one of the Eurekan research facilities, containing information on Xande's pact with the Cloud of Darkness and also contains Proto Ozma.
- The Mhachi develop a hypothesis that Xande's deal with the Cloud of Darkness is probably what led to the collapse of Allag and the disappearance of the Crystal Tower, so they know that the voidsent are dangerous and develop countermeasures against them... and here's Proto Ozma as a construct that can black hole targets into an inescapable dimensional space, which is great for (YOU GUESSED IT) sealing away voidsent.
- Once the Mhachi feel secure that they can prevent the voidsent from betraying them (with their creation of Ozma) they start summoning voidsent in earnest to use for conquest.
- When the Mhachi innovate the Nullstone as a more final countermeasure (rather than containing the voidsent within Ozma's black hole, they can just nuke the voidsent entirely) then Ozma gets repurposed as a weapon against the other city-states, but then gets placed as one of the two measures protecting the Nullstone, which is now a vulnerability for Mhach ITSELF given how much they've come to rely on summoning voidsent for power.
- ... which is why the Void Ark is still powered by imprisoned voidsent being used as batteries, even when the Mhachi realized that the flood waters were rising. They straight up never put together that their overuse of voidsent was one of the reasons WHY the Calamity of Water was coming, so they just ran with it until they couldn't any longer.
- Later on, in the 6AE, Galuf and the Students locate Proto Ozma within a Mhachi ruin and take it to the Arsenal for safekeeping, until Emmerololth shows up to start causing problems on purpose.
TL;DR: so yeah, it all comes back to the Allagans, probably.