Havemercy is set in a fictional world, and focuses primarily on two empires: Volstov and Ke-Han. There is an ongoing war between these two countries, which prompts Volstov’s ruler to have metal dragons created, and later their creators either forcibly exiled or "encouraged" to other places. Havemercy's own was prompted to go extremely far, due to Havemercy more or less being a failure in the eyes of th'Esar for no one being able to ride her when she wouldn't allow it.

Either way, she's a weapon created by humans, among other weapons from a world full of magic and misogyny at times, with a lack of any sort of technology, too.  She spends most of her time locked up until needed, and then she's unleashed upon the poor bastards who are the enemy, used to win battles that normally are won with magic and mages.

Havemercy doesn't show up much in the book that's...named after her, ironically.  She isn't in terribly much of the book and really only ever interacts with Rook and Thom. From her interactions with Rook, you can see she's obviously got a soft spot for the foul-mouthed Airman, when you wouldn't really expect her to have one for anyone at all.

She's like a cat, in a way; much of her mannerisms, from flicking her tail to lounging out and about, and being rather picky with people. She was notoriously choosy when it came to picking someone to be her rider, settling on Rook ultimately, killing or maiming people on a whim before that. Even with Rook, though, she's not terribly soft. There is a soft spot for him, but she's not afraid to be frank, or insulting, at times (such as calling him a 'common little fucker').

She doesn't really talk to Thom when Rook drags him out and onto her for a surprise ride in the middle of a raid; she asks off-handedly, who the kid is, but past that, nothing really.

Havemercy is focused when she needs to be; at one point Rook comments that she's as wicked dangerous and sharp as he is, knowing when to keep quiet and when to ask questions. She's just as foul-mouthed as her rider, though she doesn't use nearly as much slang as he does. Instead, she takes to correcting him when he uses words like "ain't". She's also neat; it's commented on that she hates the taste of soot and grease around her mouth after a fight when she's been breathing fire. Have also points out that she dislikes when Rook's are dirty; little things she doesn't have to care about, but does.