Writing Style: Conversational
If an adult has every gotten on your case about uptalk, vocal fry, or saying like all the time, you get the style of Repossessed—you and Kiriel might say different things in different ways, but you both speak the same language: teenager. Kiriel's style (which is the book's style) is colloquial and slangy, sounding a lot more like a real seventeen-year-old talking straight to you than an accomplished adult author.
Listen to the way he describes his need to get out of hell:
I was just fed up, you know; fed up with being a cog in a vast machine, with doing my pointless, demeaning job. It's not like I was the only one who could do it—anybody could do it. Tormenting the damned—it practically does itself, no lie. And it's depressing; I can't tell you how depressing it is. (1.1)
We totally get the picture of a teen saying this instead of an author. Don't you? Here's the thing: Kiriel isn't just a teen—he's a Fallen angel from another world. The author purposely uses a light and conversational tone so we can still relate to him. We end up thinking, "hey, he's a lot like me" instead of focusing on the fact that he's a millennia-old spirit with magical powers.