So I was pretty stoked for another tale of the Night Lord's 10th company as they sail boldly into oblivion. I really enjoyed Soul Hunter as it detailed the Long War from the perspective of those notorious bastards, the Night Lords. It was beautiful, showing how 200 years relative time (10,000 years absolute) will wear even a company of Space Marines down to the bone. Equipment, morale, slaves, they were running out of everything and it was up to the former Apothecary Talos to pull the Exalted's Warband out of its nosedive and restore it to the 'glory' days of its status as 10th company.
Despite being utter bastards, the characters were self-interested and thus interesting. Even Uzas, the stereotype of the Chaos Space Marine, occasionally had something more interesting to do than scream "Blood for the Blood God!" as he attempted to get the rest of the unit killed.
So I really liked Soul Hunter, the way that the author made the Astartes seem both like relatable characters from their own perspective, and monsters from the perspective of their slaves and/or victims.
Blood Reaver is more of the same, except for a deus ex machina to write the Exalted out of the picture so that Talos can assume his destiny as the leader of the warband. However, it conspicuously lacks several things, and does several worse. It lacks explanation for how the character Cyrion's telepathy seems to have disappeared. Explanation wouldn't have improved the story, but for a story that relies so heavily on continuity and characters being established in the previous novel, such an omission is grating.
I suppose that is what gets me. Neither The First Heretic nor Soul Hunter relied on pre-established knowledge and were both wonderful excusions into relatable characters, which is so rare in Warhammer 40,000. Blood Reaver faces the problems that the middle of any trilogy faces, namely that you're expected to know what's going on and it doesn't go anywhere interesting. Even when the Covenant of Blood, the cursed ship, goes down with the Exalted one board the warband has already jumped ship to an identical one.
That's not to say that the novel isn't enjoyable, or that it lacks the tone that makes the author's other books so wonderful (Space Marines suffering after-effects of combat?! Nice), it's just that it's a sequel and suffers accordingly. Finally, I'll add that my favourite part of the novel is during the seige of the Marines Errant Chapter Fortress when the Night Lords have laid the groundwork, passing the time until they stab the Blood Reaver in the back, and the Red Corsair Terminators form moving cover for First Claw to shelter behind. I think that exemplifies the Night Lords, or at least First Claw of 10th Company as the kind of bastards you should never turn your back on, or your front for that matter.