EDIT: Oh my goodddd I didn't mean for this to be so long I'm sorry!!! I get excited about things.
Ahaha, the betrayal-that-turns-into-friendship was maybe my favourite one, too. Man, the best thing would be if, near the end, the betrayal is revealed to my character, and still leads to their capture, even though by this point your character is regretting all of it! Ah, yes, very goodddd
Right, my character. I haven't decided on their gender yet! Male, female, agender, genderfluid.. I have no idea. Choosing genders for a character isn't something I put a lot of thought into because the character's gender has almost zero bearing on how I play them or their personality. (Unless it has to do with their backstory or something)
Their lifespan would be incredibly long. Depending on the strength of my demons, they live longer, so characters like Jakal could maybe be called 'conditionally immortal', while demons like Kaa have a lifespan of maybe 700 years or so?
I think I may be settling on two demon characters, though. I may end up making both in the future, but for now I only want one. One is a girl, about 40 or 50, with the appearance of a 19-year-old. She's the same type of demon as Jakal, with the black eyes. She'd look pretty human, with the exception of having black demon eyes and being able to turn into a mass of centipedes at will. She'd have vague illness/decay/poison magic and an affinity for insects and all things disgusting, and she'd be generally crass, embarrassingly sexual while actually not being interested in sex in the least, and a bit morally ambiguous. She'd always have a confident act going on, but deep down she's just really looking for a way to prove that she isn't just a disgusting blight on this earth. Getting captured by Claerth would... probably ruin her I think??? wow
The second is a raven demon (specifically a thick-billed raven, google them they're hilarious), who is kind of a self-righteous twat. He'd be the same type of demon as Kaa, with the human (well, human-ish) eyes. You know the type. Arrogant, literally always looking down his (large) nose at people, probably wants to live in some dark castle lit only by candles. He'd believe he's better than humans (and kings, and fae, and dragons, and basically anything sentient, even other demons), and would probably do some pretty awful things to prove it. He'd be pretty old, too, like.. almost a millenium old. But he'd have endearing qualities too, and with his character arc I'd be trying to develop him into a person who is more honest with their feelings, and isn't always covering them up to maintain his self image. Getting captured by Claerth would likely destroy his pride as a demon.
(I don't know if you care about how I'm handling my demons, and obviously this is unique to me only because other people have their own rules for how they handle creatures like this, but: For me, demons are characterized by their eyes, and the human-ish eyes indicate that the demon is mortal, born in the natural world, etc. etc. The eyes with black sclera indicate the type of demon that is usually stronger, and the mortal world has less of a hold on them. They're from 'beyond', whatever that might be, and can be summoned, can possess people, etc. Regardless, all of my demons can be warded against, are vulnerable to holy magic from other characters, and are also generally vulnerable to anything anyone else comes up with that is effective against 'evil' 'dark', or 'impure' things.)