This book vastly underwhelmed when you consider some of the other strong works by Virgil Knightley.
The MC is a security guy at a research facility where his whole family works, having previously spent times in the military. While waiting for his shift to start, a demon invasion happens on the planet, and the facility his family works at is at the center of it all. Rushing down, he finds his family dead, and goes on a rampage that finds him deeply wounded. He crawls into the one cryogenic chamber set up, and seals himself inside. And thus ends the prologue.
From that point forward, most of the chapters of the book are not from the MC's viewpoint. It's instead from a multitude of other people. Some are his lovers, others his comrades in arms. And the MC barely speaks in his new Hellmarine iteration. Others speak for him at times, and other times he grunts. If you get a single word from him, it's a miracle. This single facet crippled the story.
The MC has 3 women as lovers by the end of the book. The first takes one look at him and starts to ovulate. The second is an AI that can manifest a body. And the third is a rescued angel. All 3 throw themselves at the MC, who has done nothing more than exist for them to want to have sex with him. I never thought I'd see Virgil Knightley spoon feed a harem to a MC.
I really struggled to finish the book. While the plot has some interesting points, the MC was so boring that I couldn't stay focused on the book.
I will not be reading further on this series.