now I'm really thinking about my characters and how much I love them
Eiveleth and Petsaiel are twins and Tselel is their younger sibling.
Eiveleth is just SO GREAT, because she's not a nice person, but she has her own morals that she fiercely adheres to (if only somebody besides her could figure out what exactly those were) and once you're on her list of people she 'cares' about nobody but her is allowed to fuck with you. Eiveleth also REALLY REALLY likes sex. Which is just NOT an angel thing to do. Well unless you're Fallen, but even then, she's more blatant about it. She has a thing going on with Uriel's younger sister that everybody knows about and pretends not to know about. Uriel really hates her guts but can't actually do anything to her, because she's not officially part of heaven but she's not a fallen angel either, so she's in a weird grey zone. At least until she does something awful enough that they can declare her fallen. Eiveleth has a lot of abandonment issues, due to how their parents died, and her way of coping is to just not care about anybody or let them care about her. Except her siblings. Because they were similarly abandoned and are therefore her responsibility, in her eyes.
Petsaiel is... well at first glance he seems kind of straightforward. A soldier type who follows orders, and it really only good at one thing: fighting. But the only person's orders he listens to are his sister's because they trust each other above all others, and he'll follow Eiveleth anywhere. The only time he argues with her is if he thinks there's somebody they should protect. He has way more empathy than Eiveleth, and would probably be a better person overall if he'd stop listening to his sister. He's not at ALL unintelligent but Eiveleth is a lot smarter than him so he lets her do the thinking. Pet also has no interest in sex and regards Eiveleth's escapades with fond amusement. Pet is closer to Tselel than Eiveleth is, and he knows this so he makes it his responsibility to sort of make sure Tselel is at least somewhat happy. Either side of the war would absolutely LOVE to have Pet on their side, but Pet and Eiveleth are a package deal so they'd have to take Eiveleth too. (And Heaven at least is not interested in having Eiveleth, but they also don't want Hell to have her either, hence letting them stay neutral.) Eiveleth and Pet could really use some time apart but no one has ever managed to separate them.
Tselel is younger than both of them, and gets ignored frequently because s/he's good at blending into the background. (Years of practice that come from avoiding Eiveleth's temper.) Tselel is genderqueer, and until like Pet is actually interested in sex, but Tselel doesn't get a chance to really make friends let alone develop a relationship with anyone. Basically Tselel get screwed over by Eiveleth and Pet (mostly Eiveleth though) but luckily gets to actually have some agency once the main character of the story meets the siblings. Tselel is really nice and has these great puppy dog eyes that will work on absolutely anybody except for Eiveleth. Eiveleth doesn't hate Tselel though, she's just not good at caring about people. Tselel is the sort that quietly works out problems, and notices things that other people don't. Tselel is probably the most practically out of the three, if only because s/he HAS to be. Pet's good at being down to earth and practical, but places way too high of an emphasis on Eiveleth's opinion and therefore doesn't always have the best judgment. Tselel knows all of this and has gotten to the point where s/he can actually stand up to Eiveleth if she's being completely unreasonable, or if there's a practical concern that hasn't occurred to her.
Ok, I'm done now.