okay. i'll bite. ethan and kabana is a genuinely compelling pairing just because of the stark contrast between their characters.
like, ethan came into the circus jaded and apathetic and looking for a cheap thrill, got WAY more than he bargained for, and then got himself married to a nightmare incarnate that feeds off of his fear. and then he was suddenly thrust into a world of emotions he's literally never experienced before and is both very jarred and very intrigued about the entirely new perspective on life he was lended- he's spent his whole life so far surviving by dodging other people and getting himself in and out of trouble, and now his head is opened up to everything wonderful about living, and that motivates him incredibly but it also inadvertently makes him naive and easily swayed because of how new all this is to him. he's never trusted anyone in his life, but now he wants to, and he's conflicted.
enter his... wife. which okay first of all is a REALLY FUNNY SETUP. it's like the classic fairytale plot of "i'm a force of evil and i'm forcing you to marry me", and maybe i'm a sucker for goofy tropes like that being subverted into something nicer than they should be, but kabana nightmare is straight up such an insanely well written character. she's demanding and possessive and indecisive- you don't know what she wants because she doesn't know what she wants (the whole mell situation is the obvious point here), and there are very clear indications of her internal struggle through how she interacts with all the other characters. her whole job is to hurt people, and she likes doing so, but she doesn't want them to leave, so she hoards them. she has so many things, souls and suitors and all, but she doesn't have that concrete emotional connection that she really does want. she's mourning the loss of her prior relationships and she's distracting herself with newer, more colorful things that can't leave her.
and it makes their relationship so much more tangible; ethan wants to reach out and build connections because he's been deprived of them for so long, and it's refreshing to finally be able to have something that used to be literally impossible for him; kabana wants some kind of genuine love, but all she does is hurt people because of her impulses and because it's also sort of how she expresses affection. they don't mesh well, but they... want to. and that makes them sort of gravitationally pull towards each other even though at some points they make it seem like they want nothing to do with each other. they need to navigate their own emotions in order to properly work things out in a healthy way- which doesn't mean they should! any way their relationship goes has potential to be super compelling; they can get better or they can destroy each other (or a secret third option?), and their dynamic is all the more realistic because of it despite being, in practice, fantastical