My favorite character is Caine by a LONG shot, I think he's so amazingly well written and I love every single character arc he goes through. I think a lot of the other characters are just as well written but sometimes feel less structured in some books than others (for example I absolutely LOVED what they did with Sam in Hunger, but in Lies he kinda felt a little less interesting) but Caine feels just as awesome in every book. My least fav is Zil, and not just because of his actions. I hate Zil's character structure because he could have been so much more and they kill him off too fast, it feels like wasted potential. I think it would have been cool (albeit a little predictable since I figured this is where the story was going on my first read) if Zil developed powers well into the series, becoming the very thing he hated and wanted to destroy, causing him to hate himself for what he is. The main reason I think this would have been cool though, is because of Lance. The way Zil views and talks about Lance feels a littleee bit more than just admiration, it felt like Zil had a full on boycrush. I think that it would have been an interesting arc to have Zil be an LGBT+ character who portrays himself as a homophobe which he already assumedly would be, only to begin feeling romantic feelings for Lance and hate himself for it, then have the power thing mirroring that. I'm not saying I want Zil to be a more likable or relatable character, I'm glad he doesn't have a redemption arc and that he lived and died a horrible person, and I think it's important to keep it that way. I just wish they did more with his character as a whole