Those sweet summer children learned the hard way that there was a difference between the physical invulnerability they had and the one they were used to seeing in fiction. That included many other things to counter the downsides that naturally came with just being merely physically invulnerable. Things they themselves did not have, and thus it was only that moment they knew that they had messed up. As they thought that because they could not die as beta testers, instead of players. So as not to forget, they were not in their human bodies but in a virtual reality world with two layers instead of just one. The terms beta tester and player were used to determine that difference, so they did not forget they were still human and not whatever they were currently at the moment.
This gave some beta testers a false sense of reality, even within this false reality itself. One that meant that it did not matter what was done to them, that they could not be harmed as beta testers....physically. That was the magic word that they were overlooking, as Kuzas, unlike the other demons, did not learn to master the art of holding back through time and effort, of just not revealing their struggles to the world. They were not trying to paint a target on their chest and back that basically said, "Look at me, I am one of the nine demons," for all to see through their actions. Yet Kuzas was different in that regard, as they learned through trial and error of the people that learned his hand that being physically invulnerable without all the extras that normally went with it was pure nightmare fuel.
They were the example that Kuzas made for opposing him, as they still felt everything that was done to them, as being unable to be harmed in a bodily manner does not mean not being able to feel it or experience the mental and emotional damage it caused. Those poor beta testers were subjected to so much that it broke them mentally, that they either checked out mentally for good, just becoming basically punching bags for beta tester 83. They became their unofficial facility-based attack dogs that only followed beta tester 83's orders alone, as they did not have the mental capacity anymore to even log into the Avelon at this point. That or they managed to escape, or actually they were just allowed to think that, as strong enough wills they still broke, but remaining broken, however, was not their fate. They pieced themselves back together, sure, but something broken held together by duct tape and prayer is still basically broken. Repaired but not fully restored, as the cracks are still visible and just called something else at this point.
Though if Kuzas Iavko/Beta Tester 83 was being such a menace to society while partaking of various beverages within their designated areas, how was there anyone that was there still that was not just those that were made to be under their command through their usage of their sheer force and power alone? That being the thing, there were not any that were there for the dragon demon in any layer of The Decagon. That would be the thing with them, as they had those that they commanded, but they did not have anyone who was loyal to them directly and purposefully. They were all indirect, unintentional, and unofficial forces that did not rally under their banner. They were just the result of their actions alone and nothing more. The normal beta testers, players, and different types of player killers(of both layers of The Decagon) that remained were not loyal to the dragon demon at all. They were just there and could not really leave, as they lived in an isolated area, hoping that they were left alone and did not get bothered, as they did whatever it took to maintain that. Regardless of what it took to do so, they could never be considered to be any help beyond what was forced out of them.
The main bulk of what maintained the Kuza Region, both in the facility and in Avelon, was not the original thousand players. There were two kinds of people who basically what flowed in and out of them for quite some time.
The first was because they had basically reduced the player/beta tester areas to ruins with their own actions. They were open to all those who were once banned from entering to come back, as they were not coming back to a settlement or building but to ruins. Thus, all those player killers that were banned were allowed to flow back in and do whatever they wanted within this region. Backtracking a bit, this is why some of them then would not leave, as this was the only one of the ten areas where they could freely and without issue enter into the main major city or area of the facility....what is left of it at least. Some came here for the player/beta tester who were originally assigned here and could not get in because of their status. However, the majority of them were those who were here because they could wreak as much havoc and cause as much chaos as they wanted there. There was only one rule they had to follow, as that was to not piss off the massive dragon kaiju demon. Did not matter what they did otherwise, as long as they followed that one rule and expected that at any time and for any reason, that very demon could show up and do whatever they wanted, whenever they wanted, however they wanted.
The other kind of player was those who were after the hide of the Dragon Demon Kuzas Iavko in Avleon and Beta Tester 83 within the facility. They were either those who were after them because it was their goal to take down all nine demons if they wanted to eventually someday escape The Decagon. They were the broken that sought revenge and vengeance for what was done to them, as it consumed some of them to the point of madness and insanity. That was what they were there for and were allowed to do so, as the dragon demon did not take them seriously and just let them be as part of their amusement and fun. The first group also clashed with them, as this place was a paradise and they would defend to the end, as why ruin a good thing until they needed to was their thinking