Okay so Christelle Dabos is my favorite writer and one of the main thing she's good at is writing characters. Sure, there might be some narrative bits that don't hold up, or timelines that aren't clear, but her characters outshine all of that. They're compelling, you can't help but get attached to all of them. And not just because they're nuanced/morally grey. That's the bare minimum. You know how she does it ?
She takes clichés and stereotypes and plays with them. She goes beyond the archetype. Not in a "this character who seems evil turns out to be the good guy" kinda way. She's not here to refute the character traits and make a plot twist out of them. "This character seems to be evil, he's also a good guy, also does that erase his personality and all his actions beforehand ? Nope, he's still a bastard". The shy and weird girl is able to be stubborn and strong, she still remains shy and weird. The evil step-mother (or aunt, here) is actually a victim of patriarchy but hey, she's still over the top and likes to live in luxury at the end of the story. The most autistic and asocial guy you'll ever see can be a hero, he does not have to change to conform to the socially acceptable view of a hero.
Because in real life sometimes, people can be living clichés. And we don't change that easily, even after an heroic journey. Because that's still who we are.
And you know who else does this ?
Oh boy you've only read the first part of this post brace yourself.
It's not a coincidence he's my second favorite storyteller. He does the exact same thing.
And I could write a whole essay about how they both use religious figures and symbols to talk about creation. How they both have their main antagonist somehow being compared to the God of this world. How the takeaway is that sometimes creators, authors, artists, fall and lose themselves (in)to their own creation. How the main characters want to escape predetermined fate because they hate the idea that their future has been decided in advance, that they don't have free will. How even if we don't know the end of Deltarune yet, a well accepted theory, foreshadowing and subtext is that Kris will inevitably lose their hand or at least part of their mobility in their fingers, and hey, doesn't that remind you of something.
I could do that, or I could leave you with :