I wanna talk about Ryuusui cause I've been thinking about him. He's kind of an invert of (or somewhat adjacent to) the trope of living up to expectations. You become the monster because that's how people see you anyway...
He's greedy he's selfish he's self centred he's a bit of a brat and whatever other thing you can think to call a hedonist and privileged rich kid. These generally aren't seen as positive things to be, but Ryuusui takes these in stride and is proud to be all of them!
He's the greediest because he wants it all, so he can share it all. You'll have to pay for it, of course - but the option to buy it will be there. If HE'S having a good time, that means EVERYONE is capable of having a good time.
It's a funny way to turn such a negative connotation on its head.
No one will in the village will worry about starvation ever again! Why? Because I'm greedy enough to want more delicious food!
I just find it amusing and quite endearing that a character that could've so easily been annoying and grating based on the cores of his personality type, is instead a refreshing remix of those cores.
He's a rich kid, everyone was going to look at him and call him spoilt and greedy anyway. Why not take it in stride and use the power that comes with money to be greedy in the best possible way?
This also ties into what I like about Francois so much - their understanding of Ryuusui complements his more outlandish behaviour by recontextualising it.
Mild spoilers for the manga, but further on Francois acts as a translator quite often to ensure that people near them won't suffer because of a language barrier. They're able to translate and make sure concepts are understood so everyone is on the same page
Francois is incredibly perceptive (almost supernaturally so!) They are not only able to anticipate, but problem solve and create solutions based on those observations.
What we've already started to see in the anime with Francois in this one episode is how they're able to recontextualise Ryuusui! They understand that he's greedy to such a point of sincerity, and that's what keeps him moving forward.
And as it's been said, greed isn't necessarily a bad thing in this stone world. It's helping to motivate quick advancements that are going to be beneficial to everyone ;)
He's been super fun to read about and I hope he becomes even more fun as we get to see him animated. There's so many great moments coming up that will be really exciting >:)