So I've been thinking a lot about Chaos and what their game is, and what I always circle back to is what they said when Fitzroy refused to kill the prisoner.
Think about it, they said that like a pouting child who didn't get their way. They were upset with what Fitzroy did yes, but I think it was more with the method that Fitzroy did it.
Basically, he didn't use his magic.
Since Chaos' introduction, they have obviously been trying to convince Fitzroy to use their magic. To be more free, to be unrestricted and unrestrained with anything. But why? What could they possibly gain with helping Fitzroy from a separate dimension with a problem not directly afflicting them?
And it's all because of accounting.
Remember back in episode 2 with the accounting class? Finances became all the rage literally all over for kingdoms to be economically stable and contented lives. And straight straight from the owl's beak, "it was incredibly boring."
Chaos doesn't want that. They don't want order or constraint. You can't make accounting chaotic because the numbers can't lie or be disorderly in that type of math. It's not fun.
Bartholemus said this is where the hero/villain system came from, to spice up the lives of the citizens. But at the end of the day it's all an act. Villains aren't allowed to do too much evil, heroes can't divert from their heroism. There is literally a guild in charge to keep everyone in check! That's not chaos, the fights aren't chaotic, it's just an improvisional stuntshow at that point. If the whole world is staged, then the heroes and villains are but actors playing their parts.
Grey fights Hieronymous. True battles of Good and Evil. Real. Dangerous. And Chaotic.
But it didn't go the way Chaos wanted it to. Like they said, Grey is short-sighted. All he cares about is war and victory, and then the story ends. If Grey does take over the material world, all he would do is turn it into hellfire and brimstone, a new hell, and that's it. You just got rid of one stagnant society of accounting with another stagnant society of hell-extention. Granted Hell is Hell, but you can't bounce back from that! You can't just reset the world after it turns to ash, and if you can it will take a Very Long Boring Time.
The half-elf barbarian who was judged and mocked and wasn't able to produce a lick of magic. The perfect canidate for Chaos. Someone who would have validation and desire to use their power. Someone who will cause waves and make a scene wherever he goes. But most of all, someone to make the world back to what it once was.
Why do you think Fitzroy's dream is him being king? Because of Fitzroy's personality. But why set it where he is is dealing with insurgents? Chaos said it themself, Fitzroy won the civil war. He is victorious. So things should be fine now and forever with him in command. But it's not. Because it never will be. There will always be discontent. There will always be insurgents and rival fractions and revolutions and everything else that can go against an empire. And THAT is what Chaos is after. They need the cycle to continue. Rise and Fall, Build and Rebuild over and over again.
"Kingdoms rose and fell in the span of decades" back before the Age of Accounting.
Back before they were Bored.