The third beta tester was chosen to become one of the nine demons. This is where the normal bracket started, as the loser's bracket and the unique yet lacking in depth brackets. Those two were already decided. Their two spots of the nine were done; thus, as a result, the remaining seven were all entries where the person that wrote them really put some thought and depth into their choice for what their demon would be.
There were those that put a lot of thought into generic, mundane, and common choices. They were flirted out as the developers of the Decagon, the Demonlight engine, and even Kynatech itself. They did not want any of those three to be in the running outside of the two brackets specifically made for them, after all. The reasoning for that was because they were aiming for something different; thus, they did not want choices that people would come to expect, as that was why all dragons, regardless of how detailed, were automatically sorted out completely. The only one that was not was Kuzas Ivako's version because it was something that completely lacked all forms of basically anything they were looking for. There were many that just wrote what they wanted their demon form to be and even numerous people that just wrote Dragon as well. However, the choice was at random within the loser's bracket. Same for the unique yet lacking depth bracket, as Megalodon was, at the end of the day, just a giant shark. Sharks, even giant ones, were something that was pretty well known, as movies like Jaws existed, after all. The thing that got the Megalodon picked was just how unique it was, despite the lack of depth.
Though the next seven were not completely super rare and/or loosely thought of animals or creatures. The bar started at uncommon and worked its way up from there, as the depth and uniqueness of an uncommon choice could outshine anything that was merely rare or beyond, after all. So this was how the seven were the base of how the remaining seven were chosen by the system, left to make this choice from the ten thousand and nine players.
The third demon picked amongst all the eligible choices was a....
Skunk
Though it was not just a mere skunk by itself, as the reasoning for it being selected was because of the depth that was written about how the skunk would work compared to how they normally are. Known for its ability to spray a liquid with a strong, unpleasant scent as a defensive weapon. The idea that got it picked was not that it would switch from a defensive to an offensive weapon, as there were many that tried that option, and the system rejected them all after the first round of filtering the options. Merely switching a defensive weapon to offense was not able to make the cut here; thus, how did the skunk get picked as the third demon?
It was not because they made it an offensive weapon, but instead made a purely supportive one. One that would heal instead of doing anything else, as they wrote out how to turn the liquid into something that would be useful for healing, as they based their demon, if one were to use fantasy based class, into a white mage. As healing was the only thing it could do, it would also be able to cure things, mix and match with various other things as a base for whatever would be needed whenever it was needed.
Taking something that the skunk was well known for and flipping it on its head was how the choice of a demon form was selected to be one of the nine demons. However, though that was the request, the system did not give them what they wanted nor tailor the skills and abilities they would have for them. That would be up to the player, as the system did not personally create what each of the nine demons could do within the game. They were all given the freedom to do whatever they wanted, however they wanted, with what they were given. They were not given a set list of skill trees, abilities, and a list of passives to pick from. Unlike the players who have to find and learn everything on their own regardless of what it was they wanted. The nine demons were different, as they were given any and everything The Decagon had to offer the moment they were chosen to be the nine demons from that point onward. Thus, what they wanted to do and how they would do it would be solely up to them alone. Both kinds of players, those that remained as players and those that became demons. Each of them was only given what and who they were by the system based on their own choices.
How and why?
Those were things that were completely left up to them going forward, as they would determine what those two would be themselves. If they wanted something, then they would have to get it themselves. If they wanted to be something, then they would have to work for themselves as well. After all, there were not only no NPCs in The Decagon; there was also no hand holding either. That worked both ways, as there was both good and bad handholding, after all. The good is never mentioned because people do not mention or comment on things that go well normally at all. What they focus on is when things go wrong or do not work as intended. Thus, what is viewed as hand holding could just merely be the bad version of it instead of the 'good' version of it.
When?
That's another thing that's fully up to both types of overall players, even the demons that have access to everything and anything they want. A normal player's when is whenever they personally find what they are looking for. In contrast, the nine demons' when was the moment they became demons, as that was when they were given everything there was all at once. However, while they were given everything, they were not given how to use it all. That was still something they had to figure out on their own, all nine of them.