Series
There are 3 books in the Night Lords series.
Published between 2010 and 2014, in the same order they are meant to be read.
Night Lords is Aaron Dembski-Bowden's Warhammer 40,000 trilogy: Soul Hunter, Blood Reaver and Void Stalker. It follows Talos and his squad, First Claw, a warband of Chaos Space Marines from a Legion that fights through terror, long after the Horus Heresy.
All 4 books total 2,720 pages.
The Books Oracle — track the series you are partway through, and see what to read next.