Alright, here's a short analysis of the main cast of Devil Town!!
The Creator: 10/10. This guy's lived for centuries so at this point literally nothing fazes him anymore. He's also just... not wired normally? So he doesn't really feel emotions the same way as the others. The ONLY times something might actually get to him would be if it involves someone genuinely close to him (though he'd never show it, and it's not easy to be close to him XD) or if he's in really bad shape physically, like concussed or seriously injured. Otherwise, everything's just entertainment to him.
Gin: 9/10. Ex-military, so he's trained to keep his composure under pressure. Plus he spent decades alone in the Limbo, which is just an infinite foggy ocean with nothing but his own thoughts. That'll either break you or turn you into stone, and we know which option he went with XD. The only cracks are his dad and Juno being in danger.
Juno: 8/10. She's way tougher than she looks. Not physically strong, at least at first, but mentally she has dealt with a lot of stuff, including her chronic illness and being an outcast of society. So she handles nightmare scenarios very calmly. But she does lose it when The Creator actively messes with her plans or tries to hurt the people she cares about, especially Yves. She sees Yves as her equal and her responsibility, so if something happens to him it feels like her fault.
Sereph: 7/10. He doesn't seem like it at first, but he’s arguably the smartest character in the series XD He's actually super calculating and pulls off genuinely ballsy moves. But he's also emotionally closed off, covering his real feelings by being rude or whatever keeps people at a distance. His weak spots are Gin and his past. And here's the thing: Juno isn't exactly the most "moral" person herself, so she gets him on some level, which pisses him off because he doesn't want to be understood, especially not by her.
Yves: 4/10. I love him sooooooo much. He's the most reactive of the group, and it's not mailce, it's just trauma and insecurity. He's hyper-aware that people value him for his looks rather than his actions, and he totally hates that, it makes him feel sick about himself. When he fails at something or feels useless compared to the more competent characters around him, he doesn't explode or anything, doesn't get rude. Instead he gets self deprecating on the inside, but outwards covers it with humor and fake it till you make it stuff, but sometimes it doesn't really work out. He's easy to rattle because he's constantly fighting his own sense of worthlessness. But that emotional mess is also what makes him brave enough to act when it counts, unlike the others who might think too much about what to do next.