Demons: Bloodlust by Hyena Hall

Hell is exactly as you imagine it: a bloated bureaucracy of tedious procedures and arbitrary rules! Here, infernal incubus Skud enjoys a much more luxurious life than his pit demon sibling, Bug. But when his repeated rule-breaking gets him in trouble with his boss, the only way out of a permanent demotion is a simple vampire-slaying mission up on Earth. (Turns out, the paper-pushers in hell aren’t big fans of the loopholes that vampires create). Enlisting the aid of his more violent sibling, the two embark on what should be a fairly straightforward mission… unless of course, it’s not.